davidbgk
/
larlet-fr-david-cache

<!doctype html><!-- This is a valid HTML5 document. -->
<!-- Screen readers, SEO, extensions and so on. -->
<html lang="fr">
<!-- Has to be within the first 1024 bytes, hence before the <title>
  See: https://www.w3.org/TR/2012/CR-html5-20121217/document-metadata.html#charset -->
<meta charset="utf-8">
<!-- Why no `X-UA-Compatible` meta: https://stackoverflow.com/a/6771584 -->
<!-- The viewport meta is quite crowded and we are responsible for that.
  See: https://codepen.io/tigt/post/meta-viewport-for-2015 -->
<meta name="viewport" content="width=device-width,initial-scale=1">
<!-- Required to make a valid HTML5 document. -->
<title>On Pair Programming (archive) — David Larlet</title>
<!-- Generated from https://realfavicongenerator.net/ such a mess. -->
<link rel="apple-touch-icon" sizes="180x180" href="/static/david/icons2/apple-touch-icon.png">
<link rel="icon" type="image/png" sizes="32x32" href="/static/david/icons2/favicon-32x32.png">
<link rel="icon" type="image/png" sizes="16x16" href="/static/david/icons2/favicon-16x16.png">
<link rel="manifest" href="/static/david/icons2/site.webmanifest">
<link rel="mask-icon" href="/static/david/icons2/safari-pinned-tab.svg" color="#07486c">
<link rel="shortcut icon" href="/static/david/icons2/favicon.ico">
<meta name="msapplication-TileColor" content="#f0f0ea">
<meta name="msapplication-config" content="/static/david/icons2/browserconfig.xml">
<meta name="theme-color" content="#f0f0ea">
<!-- Thank you Florens! -->
<link rel="stylesheet" href="/static/david/css/style_2020-01-24.css">
<!-- See https://www.zachleat.com/web/comprehensive-webfonts/ for the trade-off. -->
<link rel="preload" href="/static/david/css/fonts/triplicate_t4_poly_regular.woff2" as="font" type="font/woff2" crossorigin>
<link rel="preload" href="/static/david/css/fonts/triplicate_t4_poly_bold.woff2" as="font" type="font/woff2" crossorigin>
<link rel="preload" href="/static/david/css/fonts/triplicate_t4_poly_italic.woff2" as="font" type="font/woff2" crossorigin>

  <meta name="robots" content="noindex, nofollow">
  <meta content="origin-when-cross-origin" name="referrer">
  <!-- Canonical URL for SEO purposes -->
  <link rel="canonical" href="https://martinfowler.com/articles/on-pair-programming.html">

<body class="remarkdown h1-underline h2-underline hr-center ul-star pre-tick">

<article>
<h1>On Pair Programming</h1>
<h2><a href="https://martinfowler.com/articles/on-pair-programming.html">Source originale du contenu</a></h2>
<blockquote>
<p>Betty Snyder and I, from the beginning, were a pair. And I believe that
      the best programs and designs are done by pairs, because you can criticise
      each other, and find each others errors, and use the best ideas.</p>

<p class="quote-attribution">-- <a href="http://www.computerhistory.org/revolution/birth-of-the-computer/4/78/2258">Jean Bartik, one of the very first programmers</a></p>
</blockquote>

<blockquote>
<p>Write all production programs with two people sitting at one machine.</p>

<p class="quote-attribution">-- <a href="https://www.amazon.com/gp/product/0321278658?ie=UTF8&amp;tag=martinfowlerc-20&amp;linkCode=as2&amp;camp=1789&amp;creative=9325&amp;creativeASIN=0321278658">Kent Beck</a><img src="https://www.assoc-amazon.com/e/ir?t=martinfowlerc-20&amp;l=as2&amp;o=1&amp;a=0321601912" border="0" alt=""/></p>
</blockquote>

<p>Jean Bartik was one of the <a href="https://en.wikipedia.org/wiki/ENIAC#Programmers">ENIAC women</a>, who are considered by many to be the very first programmers.
    They took on the task of programming when the word "program" was not even used yet,
    and there were no role models or books to tell them how to do this - and they
    decided that it would be a good idea to work in a pair. It took about 50
    more years for pair programming to become a widespread term, when
    Kent Beck described the term in his book "Extreme Programming" in the late
    1990s. The book introduced agile software development practices to a wider
    audience, pairing being one of them. </p>

<p>Pair programming essentially means that two people write code together on one machine. It is a very collaborative way of working and involves a lot of communication. While a pair of developers
    work on a task together, they do not only write code, they also plan and discuss
    their work. They clarify ideas on the way, discuss approaches and come
    to better solutions.</p>

<p>The first part of this article, <a href="#HowToPair">"How to
    pair"</a>, gives an overview of different practical approaches to pair
    programming. It's for readers who are looking to get started with pairing,
    or looking to get better at it.</p>

<p>The second and third parts, <a href="#Benefits">"Benefits"</a>
    and <a href="#Challenges">"Challenges"</a>, dive deeper into
    what the goals of pair programming are, and how to deal with the challenges
    that can keep us from those goals. These parts are for you if you want to
    understand better why pair programming is good for your software and your
    team, or if you want some ideas what to improve.</p>

<p>Part four and five, <a href="#ToPairOrNotToPair">"To pair or not
    to pair?"</a>, and <a href="#ButReallyWhyBother">"But really, why bother?"</a>,
    will conclude with our thoughts on pairing in the grand scheme of team flow
    and collaboration.</p>

<section id="HowToPair">
<h2>How to pair</h2>

<section id="Styles">
<h3>Styles</h3>

<section id="DriverAndNavigator">
<h4>Driver and Navigator</h4>

<p>These classic pair programming role definitions can be applied in
          some way or other to many of the approaches to pairing.</p>

<p>The <b>Driver</b> is the person at the wheel, i.e. the keyboard. She is
          focussed on completing the tiny goal at hand, ignoring larger issues
          for the moment. A driver should always talk through what she is doing
          while doing it.</p>

<p>The <b>Navigator</b> is in the observer position, while the driver is
          typing. She reviews the code on-the-go, gives directions and shares
          thoughts. The navigator also has an eye on the larger issues, bugs,
          and makes notes of potential next steps or obstacles.</p>

<p>The idea of this role division is to have two different
          perspectives on the code. The driver's thinking is supposed to be more
          tactical, thinking about the details, the lines of code at hand. The
          navigator can think more strategically in their observing role. They
          have the big picture in mind.</p>

<p>A common flow goes like this:</p>

<ul>
<li>Start with a reasonably well-defined task</li>

<li>Agree on one tiny goal at a time. This can be defined by a unit
            test, or by a commit message, or written on a sticky note.</li>

<li>Switch keyboard and roles regularly. Shared active participation
            keeps the energy level up and we learn and understand things
            better.</li>

<li>As navigator, avoid the "tactical" mode of thinking, leave the
            details of the coding to the driver - your job is to take a step back
            and complement your pair's more tactical mode with medium-term
            thinking. Park next steps, potential obstacles and ideas on sticky
            notes and discuss them after the tiny goal is done, so as not to
            interrupt the driver's flow.</li>
</ul>
</section>

<section id="PingPong">
<h4>Ping Pong</h4>


<p>This technique embraces <a href="https://martinfowler.com/bliki/TestDrivenDevelopment.html">Test-Driven Development</a> (TDD)
          and is perfect when you have a clearly defined task that can be
          implemented in a test-driven way.</p>

<ul>
<li>"Ping": Developer A writes a failing test</li>

<li>"Pong": Developer B writes the implementation to make it pass.</li>

<li>Developer B then starts the next "Ping", i.e. the next failing
            test.</li>

<li>Each "Pong" can also be followed by refactoring the code together,
            before you move on to the next failing test. This way you follow the
            "Red - Green - Refactor" approach: Write a failing test (red), make it
            pass with the minimum necessary means (green), and then <a href="https://martinfowler.com/tags/refactoring.html">
            refactor</a>.</li>
</ul>


</section>

<section id="Strong-stylePairing">
<h4>Strong-Style Pairing</h4>

<p>This is a technique particularly useful for knowledge transfer,
          described in much more detail by Llewellyn Falco <a href="https://llewellynfalco.blogspot.com/2014/06/llewellyns-strong-style-pairing.html">here.</a></p>

<p>The rule: "For an idea to go from your head into the computer it
          MUST go through someone else's hands". In this style, the navigator is
          usually the person much more experienced with the setup or task at
          hand, while the driver is a novice (with the language, the tool, the
          codebase, ...). The experienced person mostly stays in the navigator
          role and guides the novice.</p>

<p>An important aspect of this is the idea that the driver totally
          trusts the navigator and should be "comfortable with incomplete
          understanding". Questions of "why", and challenges to the solution
          should be discussed after the implementation session. In a setting
          where one person is a total novice, this can make the pairing much
          more effective.</p>

<p>While this technique borders on micro-management, it can be a
          useful onboarding tool to favor active "learning by doing" over
          passive "learning by watching". This style is great for initial
          knowledge transfer, but shouldn't be overused. Keep in mind that the
          goal is to be able to easily switch roles after some time, and ease
          out of the micro management mode. That will be a sign that the
          knowledge transfer worked.</p>
</section>

<section id="PairDevelopment">
<h4>Pair Development</h4>

<p>"Pair Development" is not so much a specific technique to pair, but
          more of a mindset to have about pairing. (We first came across the
          term in <a href="https://twitter.com/sarahmei/status/877738639991611392">this thread</a> on
          Sarah Mei's Twitter account.) The development of a <a href="https://martinfowler.com/bliki/UserStory.html">user story</a> or a
          feature usually requires not just coding, but many other tasks. As a
          pair, you're responsible for all of those things.</p>

<p>To help get you into the mindset, the following are a few examples
          of the non-coding activities in a story life cycle that benefit from
          pairing.</p>

<section id="">
<p class="pairing-subheading">Planning - what's our goal?</p>

<p>When you first start working on something together, don't jump
            immediately into the coding. This early stage of a feature's life
            cycle is a great opportunity to avoid waste. With four eyes on the
            problem this early on, catching misunderstandings or missing
            prerequisites can save you a lot of time later.</p>

<ul>
<li><b>Understand the problem:</b> Read through the story and play back to
              each other how you understand it. Clear up open questions or potential
              misunderstandings with the Product Owner. If you have a
              <a href="https://www.agilealliance.org/glossary/definition-of-ready/">Definition of Ready</a> in your
              team, go through that again and make sure you have everything to get
              started.
            </li>

<li><b>Come up with a solution:</b> Brainstorm what potential solutions for
              the problem are. You can either do this together, or split up and then
              present your ideas to each other. This depends on how well-defined the
              solution already is, but also on your individual styles. Some people
              like some time to think by themselves, others like talking things
              through out loud while they are thinking. If one of you is less
              familiar with the domain or tech, take some time to share the
              necessary context with each other.
            </li>

<li><b>Plan your approach:</b> For the solution you chose, what are the steps
              you need to take to get there? Is there a specific order of tasks to
              keep in mind? How will you test this? Ideally, write these steps down,
              in a shared document or on sticky notes. That will help you keep track
              of your progress, or when you need to onboard somebody else to help work on the task. Writing this down also simply helps remember
              what needs to be done - in the moment, we too often underestimate how
              many things we will have forgotten even as quickly as the next
              day...
            </li>
</ul>
</section>

<section id="">
<p class="pairing-subheading">Research and explore</p>

<p>When implementing a feature that requires you to use a technology
            you are both unfamiliar with, you'll have to do some research and
            exploration first. This work does not fit into the clean-cut
            "driver-navigator" or "ping-pong" approaches. E.g., browsing search
            engine results together on the same screen is usually not very
            effective.</p>

<p>Here is one way to approach this in pair development mode:</p>

<ul>
<li>Define a list of questions that you need to answer in order to come
              up with a suitable solution.</li>

<li>Split up - either divide the questions
              among you, or try to find answers for the same questions separately.
              Search the internet or other resources within your organisation to
              answer a question, or read up on a concept that is new to both of
              you.</li>

<li>Get back together after a previously agreed upon timebox and
              discuss and share what you have found.</li>
</ul>
</section>

<section id="">
<p class="pairing-subheading">Documentation</p>

<p>Another thing to work on together beyond the code is documentation. 
            Reflect together if there is any documentation necessary for what
            you've done. Again, depending on the case at hand and your individual
            preferences, you can either create the documentation together, or have
            one of you create it, then the other review and word-smith.</p>

<p>Documentation is a great example of a task where a pair can
            keep each other disciplined. It's often a task left for
            last, and when it's the last thing keeping us from the great feeling
            of putting our story into "Done", then more often than not, we skip
            it, or "wing it". Working in a pair keeps us honest about some of the
            valuable, but annoying things that we'll be very thankful for in the
            future.</p>
</section>
</section>
</section>

<section id="TimeManagement">
<h3>Time management</h3>


<p>In addition to the general styles for pairing, there are other little tools and techniques to make it easier.</p>

<p>The pomodoro technique is ones of those tools. It is a time management method that breaks work
        down into chunks of time - traditionally 25 minutes - that are
        separated by short breaks. The technique can be applied to almost all
        of the pairing approaches described and will keep you focused. Pairing
        can be an exhausting practice, so it is helpful to get a reminder to
        take breaks and to switch the keyboard regularly.</p>

<p>Here is an example of how using the pomodoro technique looks like
        in practice.</p>

<ul>
<li>Decide on what to work on next</li>

<li>Set a timer for 25 minutes, e.g. with the help of the many pomodoro
          browser extensions - or even a real life tomato shaped kitchen
          timer...</li>

<li>Do some work without interruptions</li>

<li>Pause work when the timer rings - start with short breaks (5-10
          minutes)</li>

<li>After 3 or 4 of these "pomodoros", take a longer break (15–30 minutes)</li>

<li>Use the short breaks to <i>really</i> take a break and tank energy, get some water or
          coffee, use the bathroom, get some fresh air. Avoid using these short
          breaks for other work, like writing emails.</li>
</ul>
</section>

<section id="PairRotations">
<h3>Pair Rotations</h3>

<p>Rotating pairs means that after working together for some time, one
        half of the pair leaves the story, while the other person onboards
        somebody new to continue. The person who stays is often called the
        "anchor" of a story.</p>

<p>One category of reasons why to rotate is logistics. Your pairing
        partner could be sick or going on holiday. Or one of you is working
        remotely for a day, and the work requires physical presence on site, e.g.
        because there is a hardware setup involved.</p>

<p>Another group of reasons why to rotate is to mix things up. Either
        the two of you have been working together for a while and are starting
        to show signs of "cabin fever" because you are spending too much time
        together. Or you're working on something very tedious and
        energy-draining - a rotation will give one of you a break, and a new
        person can bring in some fresh perspectives and energy.</p>

<p>Finally, the most given reason for pair rotations is to avoid
        knowledge silos, increase collective code ownership, and get some more code
        review on-the-go. Pairing itself is already helping with those things,
        but rotations can further increase the average number of eyes on each
        line of code that goes to production.</p>

<p>As to the ideal frequency of rotations, this is where opinions
        diverge. Some people believe that rotations every 2-3 days are crucial
        to ensure a sufficient knowledge spread and quality. Every rotation
        comes with some costs though. There's the time to onboard a new
        person, and the cost of a context switch for one of the two. If there
        is no constant anchor for continuity, the risk increases that tacit
        knowledge about the problem and solution space gets lost and triggers
        rework. For more junior developers it's sometimes more beneficial to
        stay on something for longer, so they have sufficient time to immerse
        themselves in a topic and give new knowledge time to settle.</p>


<p>Think about the trade off between these costs and the benefits. For
        example, let's say you have high quality knowledge sharing already,
        with team "show and tells", readable code and good documentation. In
        that case, maybe an insistence on frequent rotations only marginally
        improves your collective code ownership, while creating high amounts
        of friction and overhead.</p>
</section>

<section id="PlanTheDay">
<h3>Plan the Day</h3>

<p>Pairing requires a certain level of scheduling and calendar
        coordination. If you don't take time to acknowledge and accommodate
        this, it will come back to haunt you later in the day.</p>

<p>Start the day with a calendar check - agree with your pairing
        partner on how many hours you are going to pair, and see if you need
        to plan around meetings or time needed to work on other things outside
        of the pairing task. If it turns out that one of you will have to work
        by themselves for a while, then make sure to prepare for things to
        continue without the other person, e.g. by not using that person's
        computer to code.</p>

<p>If you have meetings or other commitments during the day, make sure
        you have a reminder in place that you will notice, especially when
        working on your pairing partner's machine. If your team pairs by
        default, consider agreeing on regular "core coding hours" for
        everyone. This makes scheduling much easier.</p>
</section>

<section id="PhysicalSetup">
<h3>Physical Setup</h3>

<p>Pair programming means you need to work very closely together in
        the physical space of one shared desk. This is quite different from
        having your own table to spread out on. Being that close to one
        another requires a certain level of respect and attention for each
        other's needs. That is why it is worth spending some time figuring out
        a comfortable setup for both of you.</p>

<ul>
<li>Make sure both of you have enough space, clear up the desk if
          necessary.</li>

<li>Is there enough space for both chairs in front of the desk? Get
          waste bins and backpacks out of the way.</li>

<li>Do you want to use two keyboards or one? Same for the mouse, one or
          two? There's no clear rule that always works, we recommend you try out
          what works best for each situation. Some of the factors that play into
          this are hygiene, how good you are at sharing keyboard time, or how
          much space you have available.</li>

<li>Do you have an external monitor available, or maybe even two? If
          not, you can also consider setting up some kind of screen sharing, as
          if you were remote pairing. In that setup, each of you would use their
          own laptop keyboards.</li>

<li>Check with your partner if they have any particular preferences or
          needs (e.g. larger font size, higher contrast, ...)</li>

<li>If you have an unusual keyboard/IDE setup check with your partner
          if they are okay with it. See if you can have a simple mechanism to
          switch your settings back to a more standard configuration for these
          situations.</li>
</ul>

<p>It is beneficial if your team can agree on a default setup, so that
          you don't have to discuss these things again and again.</p>
</section>

<section id="RemotePairing">
<h3>Remote Pairing</h3>

<p>Are you part of a distributed team, or some team members
        occasionally work from home? You can still practice pair programming, as long as both of you have reasonably stable internet access.</p>

<section id="">


<p class="pairing-subheading">The Setup</p>

<p>For remote pairing, you need a screen-sharing solution that allows you to
          not only see, but also control the other person's machine, so that you are
          able to switch the keyboard. Many video conferencing tools today already
          support this, so if you're working at a company who has a license for a
          commercial VC tool, try that first. There are also open source tools for video
          calls with remote control, e.g. <a href="https://jitsi.org">jitsi</a>. For solutions
          that work at lower bandwidths, try things like <a href="https://www.hamvocke.com/blog/remote-pair-programming-with-tmux/">
          ssh with tmux</a> or the <a href="https://visualstudio.microsoft.com/services/live-share/">Live Share
          extension for Visual Studio Code</a>.</p>
</section>

<section id="">
<p class="pairing-subheading">Tips</p>

<ul>
<li><b>Use video:</b> Since people communicate a lot through gestures and facial
            expressions it is nice to see the shared screen and your
            pairing partner's video at the same time. Some video conference solutions come with this feature; if yours doesn't, consider opening up an additional call in order to see each other. </li>

<li><b>Planning and designing:</b> Use collaborative online visualization tools, to reproduce
            the experience of sketching out things on paper or a whiteboard.</li>

<li><b>Audio experience:</b> Look for a quiet area and use a good headset, maybe even
            with a directional microphone. If you can't get away from the noise, "push to
            speak" functionality can also help. To avoid distractions on your side,
            noise-cancelling headphones are your friend.</li>


<li>Dealing with network lag: It can be exhausting to work on a remote computer
            for a longer period of time when there is a network lag. So make sure to
            switch computers regularly, so that each of you has a chance to work on their
            own machine without lag. A network lag can also be annoying when you scroll
            through files because it can be hard to follow. It helps to avoid scrolling in
            long files, try to use keyboard shortcuts to open different parts of the file
            or use the collapse/uncollapse functionality instead.</li>
</ul>
</section>

<section id="">
<p class="pairing-subheading">The Human Part</p>

<p>If you work in a setup where not the whole team is distributed and just one
          or a few of you are remote, try to include the remote partner in all
          discussions that are happening in the office. We tend to forget how much we
          share incidentally just by sitting in the same room.</p>

<p>Working remotely with someone you haven't met and do not know creates an
          additional challenge. On the one hand, pairing is a chance to get closer to each
          other on a remote team. On the other hand, it's sometimes easy to forget that
          part of the collaboration. If there is no chance that you meet in person, think about other ways
          to get to know each other a bit better, e.g. try to have a remote coffee
          together.</p>

<p>Finally, while remote pairing can have its challenges, it can also make it easier to focus than when pairing on site, because it
          is easier to blend out distractions with headphones on.</p>
</section>
</section>

<section id="HaveADonutTogether">
<h3>Have a Donut Together</h3>

<p>Celebrate when you have accomplished a task together! High-fiving
        each other might seem corny, but it's actually a little "power pose"
        you can do together that can energize and get you ready for the next
        task. Or maybe you create your own way of celebrating success, like
        Lara Hogan, who celebrates career achievements with a <a href="https://larahogan.me/donuts/">
        donut</a>.</p>
</section>

<section id="ThingsToAvoid">
<h3>Things to Avoid</h3>

<p>The different approaches and techniques help you to have a
        better pairing experience. Here are a few common pitfalls to avoid:</p>

<section id="">
<p class="pairing-subheading">Drifting apart</p>

<p>When you pair, avoid to read emails or to use your phone. These distractions might come across
          as direspectful to your pair, and they distract you from the task you are working on. 
          If you really need to check
          something, make it transparent what you are doing, and why. Make sure that everyone has
          enough time to read their emails by taking enough breaks and reserving some
          individual time each day.</p>
</section>

<section id="">
<p class="pairing-subheading">Micro-Management Mode</p>

<p>Watch out for micro-management mode: It doesn't leave room for
          the other person to think and is a frustrating experience, if
          someone keeps giving you instructions like:</p>

<ul>
<li>"Now type 'System, dot, print, "...</li>

<li>"Now we need to create a new class called..."</li>

<li>"Press command shift O..."</li>
</ul>
</section>

<section id="">
<p class="pairing-subheading">Impatience</p>

<p>Apply the "5 seconds rule": When the navigator sees the driver do
            something "wrong" and wants to comment, wait at least 5 seconds
            before you say something - the driver might already have it in mind,
            then you are needlessly interrupting their flow.</p>

<p>As Navigator, don't immediately point out any error or upcoming
            obstacle: Wait a bit for the driver to correct or write a sticky
            note to remember later. If you intervene immediately, this can be
            disruptive to the driver's thinking process.</p>
</section>

<section id="">


<p class="pairing-subheading">Keyboard Hogging</p>

<p>Watch out if you're "hogging the keyboard": Are you controlling
            it all the time, not letting your pairing partner do some typing as well?</p>

<p>This can be a really annoying experience for your pair and might cause them having
            a hard time focussing because of limited "active participation". Try
            one of the approaches described earlier to make sure that you switch
            the keyboard frequently.</p>
</section>

<section id="">
<p class="pairing-subheading">Pairing 8 Hours per Day</p>

<p>Teams that are really committed to making pair programming work
            sometimes end up pairing for 8 hours a day. In our experience, that
            is not sustainable. First of all it is just too exhausting. And
            secondly, it does not even work in practice because there are so
            many other things you do other than coding, e.g. checking emails,
            having 1:1s, going to meetings, researching/learning. So keep that
            in mind when planning your day and don't assume it will be 100%
            coding together.</p>
</section>
</section>

<section id="ThereIsNottheRightWay">
<h3>There is not "THE" right way</h3>

<p>There are many approaches to pair programming and there is not
        "THE" right way to do it. It depends on your styles, personalities,
        experience, the situation, the task and many other factors. In the
        end, the most important question is: Do you get the promised benefits
        out of it? If this is not the case, try out something else, reflect,
        discuss and adjust to get them.</p>
</section>
</section>

<section id="Benefits">
<h2>Benefits</h2>

<p>What is pair programming good for? Awareness of all its potential
      benefits is important to decide when you do it, how to do it well, and to
      motivate yourself to do it in challenging times. The main goals pairing
      can support you with are software quality and team flow.</p>


<p>How can pairing help you achieve those goals then?</p>

<section id="KnowledgeSharing">
<h3>Knowledge Sharing</h3>

<p>Let's start with the most obvious and least disputed benefit of
        pairing: Knowledge sharing. Having two people work on a piece of the
        code helps the team spread knowledge on technology and domain on a daily
        basis and prevents silos of knowledge. Moreover, when two minds
        understand and discuss a problem, we improve the chances of finding a
        good solution. Different experiences and perspectives will lead to the
        consideration of more alternatives. </p>

<section id="">
<p class="pairing-subheading">Practical Tips</p>

<p>Don't shy away from pairing on tasks when you have no idea about
          the technology involved, or the domain. If you keep working in the
          area that you feel most comfortable in, you will miss out on learning
          new things, and ultimately spreading
          knowledge in your team.</p>

<p>If you notice that a team member tends
          to work on the same topics all the time, ask them to mix it up to
          spread their expertise. It can also help to create a skill matrix with
          the team's tech &amp; business topics and each person's strengths and
          gaps in each area. If you put that on a wall in your team area, you
          can work together on getting a good spread of knowledge.</p>
</section>
</section>

<section id="Reflection">
<h3>Reflection</h3>

<p>Pair programming forces us to discuss approaches and solutions,
        instead of only thinking them through in our own head. Saying and
        explaining things out loud pushes us to reflect if we really have the
        right understanding, or if we really have a good solution. This not only
        applies to the code and the technical design, but also to the user story
        and to the value a story brings.</p>

<section id="">
<p class="pairing-subheading">Practical Tips</p>

<p>It requires trust between the two of you to create an atmosphere in
          which both of you feel free to ask questions and also speak openly
          about things you don't understand. That's why building relationships
          within the team becomes even more important when you pair. Take time
          for regular 1:1 and feedback sessions.</p>
</section>
</section>

<section id="KeepingFocus">
<h3>Keeping focus</h3>

<p>It's a lot easier to have a structured approach when there are two of
        you: Each of you has to explicitly communicate why you are doing
        something and where you are heading. When working solo, you can get
        distracted a lot easier, e.g. by "just quickly" trying a different
        approach without thinking it through, and then coming back out of the
        rabbit hole hours later. Your pairing partner can prevent you from
        going down those rabbit holes and focus on what is important to finish
        your task or story. You can help each other stay on track.</p>

<section id="">
<p class="pairing-subheading">Practical Tips</p>

<p>Make plans together! Discuss your task at hand and think about
          which steps you need to make to reach your goal. Put each of the steps
          on sticky notes (or if remotely, subtasks in your ticket management
          system), bring them in order and go one by one. Try this in
          combination with the <a href="#TimeManagement">Pomodoro technique</a> and try to finish one of the goals in one pomodoro.</p>

<p>Never forget that communication is key. Talk about what you are
          doing and demand explanations from each other.</p>
</section>
</section>

<section id="CodeReviewOn-the-go">
<h3>Code review on-the-go</h3>

<p>When we pair, we have 4 eyes on the little and the bigger things as
        we go, more errors will get caught on the way instead of after we're
        finished.</p>

<p>The <a href="https://martinfowler.com/tags/refactoring.html">refactoring</a> of code is always part of coding, and therefore of pair
        programming. It's easier to improve code when you have someone beside
        you because you can discuss approaches or the naming of things for
        example.</p>

<p>Doing code reviews after the fact has some downsides. We will dive
        more into this later, in <a href="#ToPairOrNotToPair">"To pair or
        not to pair?"</a>.</p>

<section id="">
<p class="pairing-subheading">Practical Tips</p>

<p>Ask each other questions! Questions are the most powerful tool to
          understand what you are doing and to come to better solutions. If code
          is not easy to read and understand for one of you, try a different way
          that is easier to understand.</p>

<p>If you feel the need to have more code review on pair programmed
          code, reflect if you can improve your pairing. Weren't you able to
          raise all questions and concerns during your pairing session? Why is
          that? What do you need to change?</p>
</section>
</section>

<section id="TwoModesOfThinkingCombined">
<h3>Two modes of thinking combined</h3>

<p>As mentioned when we described the classic 
        <a href="#DriverAndNavigator">driver/navigator</a> style
        earlier, pairing allows you to have different perspectives on the code.
        The driver's brain is usually more in "tactical" mode, thinking about
        the details, the current line of code. Meanwhile, the navigator's brain
        can think more strategically, consider the big picture, park next steps
        and ideas on sticky notes. Could one person combine these two modes of
        thinking? Probably not! Having a tactical and strategic view combined
        will increase your code quality because it will allow you to pay
        attention to the details while also having the bigger picture in
        mind.</p>

<section id="">
<p class="pairing-subheading">Practical Tips</p>

<p>Remember to switch the keyboard and thus the roles regularly. This
          helps you to refresh, to not get bored, and to practice both ways of
          thinking.</p>

<p>As navigator, avoid the "tactical" mode of thinking, leave the
          details of the coding to the driver - your job is to take a step back
          and complement your pair's more tactical mode with medium-term
          thinking.</p>
</section>
</section>

<section id="CollectiveCodeOwnership">
<h3>Collective Code Ownership</h3>

<blockquote>
<p>Collective code ownership abandons any notion of individual
          ownership of modules. The code base is owned by the entire team and
          anyone may make changes anywhere.</p>

<p class="quote-attribution">-- <a href="https://www.martinfowler.com/bliki/CodeOwnership.html">Martin Fowler</a></p>
</blockquote>

<p>Consistent pairing makes sure that every line of code was touched or
        seen by at least 2 people. This increases the chances that anyone on the
        team feels comfortable changing the code almost anywhere. It also makes
        the codebase more consistent than it would be with single coders
        only.</p>

<section id="">
<p class="pairing-subheading">Practical Tips</p>

<p>Pair programming alone does not guarantee you achieve collective
          code ownership. You need to make sure that you also rotate people
          through different pairs and areas of the code, to prevent knowledge
          silos.</p>
</section>
</section>

<section id="KeepsTheTeamsWipLow">
<h3>Keeps the team's WIP low</h3>

<p>Limiting work in progress is one of the core principles of Kanban to
        improve team flow. Having a <a href="https://dzone.com/articles/the-importance-of-wip-limits">Work in Progress (WIP)
        limit</a> helps your team focus on the most important tasks. Overall
        team productivity often increases if the team has a WIP limit in place,
        because multi-tasking is not just inefficient on an individual, but also on the team level.
        Especially in larger teams, pair programming limits the number of things
        a team can work on in parallel, and therefore increases the overall
        focus. This will ensure that work constantly flows, and that blockers are
        addressed immediately.</p>

<section id="">
<p class="pairing-subheading">Practical Tips</p>

<p>Limit your team's WIP to the number of developer pairs on your team
          and make it visible in your team space (or, if you work remotely, in your
          online project management tool). Have an eye on the limit before picking up
          new tasks. WIP limit discipline might naturally force you into a
          pairing habit.</p>
</section>
</section>

<section id="FastOnboardingOfNewTeamMembers">
<h3>Fast onboarding of new team members</h3>

<p>Since pairing facilitates knowledge sharing it can help with the
        onboarding of new team members. New joiners can get to know the project,
        the business and the organisation with the help of their pair. Changes
        in a team have an impact on the team flow. People just need some time to
        get to know each other. Pair programming can help to minimize that
        impact, because it forces people to communicate a lot more than they
        need when working solo.</p>

<section id="">
<p class="pairing-subheading">Practical Tips</p>

<p>It is not enough to just put new joiners into a pair, and then they
          are "magically" included and onboarded. Make sure to provide the big
          picture and broader context before their first pairing session, and
          reserve some extra time for the onboarding. This will make it easier
          for them to follow along and contribute during the pairing, and get
          the most out of it. Always use the new joiners' machine when pairing, to make sure that
            they are set up to work by themselves as well.</p>

<p>Have an onboarding plan with a list of topics to cover. For some topics you might want to schedule dedicated sessions, for other topics the new
          team member can take the onboarding plan with her from pair to pair. If something is covered in
          the pairing session, you can check it off the list. This way
          the onboarding progress is visible to everyone on the team. </p>
</section>
</section>
</section>

<section id="Challenges">
<h2>Challenges</h2>

<p>While pair programming has a lot of benefits, it also requires practice and
      might not work smoothly from the start. The following is a list of some of the common challenges teams
      experience, and some suggestions on how to cope with them. When you come across
      these challenges, keep the benefits in mind and remember why you pair.
      It is important to know what you want to achieve with a practice, so that
      you can adjust the way you do it.</p>

<section id="PairingCanBeExhausting">
<h3>Pairing can be exhausting</h3>

<p>When working alone, you can take breaks whenever you want, and your mind
        can drift off or shut down for a bit when it needs to. Pairing forces
        you to keep focus for potentially longer stretches of time, and find common ground
        with the other person's rhythm and ways of thinking. The increased focus
        is one of the benefits of pairing, but can also make it quite intense and
        exhausting.</p>


<section id="">
<p class="pairing-subheading">Ways to tackle</p>

<p>Taking enough breaks is key to face this challenge. If you notice
          you are forgetting to take regular breaks, try scheduling them with an
          alarm clock, for example 10 minutes per hour. Or use a time management
          technique like <a href="#TimeManagement">Pomodoro</a>. 
          Don't skip your lunch break: Get away from
          the monitor and take a real break. Pairing or not, taking breaks is
          important and increases productivity.</p>

<p>Another important thing to prevent exhaustion is to not pair 8
          hours per day. Limit it to a maximum of 6 hours per day. Regularly
          switching roles from driver to navigator can also help to keep the
          energy level up.</p>
</section>
</section>

<section id="IntenseCollaborationCanBeHard">
<h3>Intense collaboration can be hard</h3>

<p>Working so closely with another person for long stretches of time is
        intense. You need to communicate constantly and it requires empathy and
        interpersonal skills.</p>

<p>You might have
        differences in techniques, knowledge, skills, extraversion,
        personalities, or approaches to problem-solving. Some combinations of those might
        not match well and give you a rocky start. In that case, you need to invest some time to
        improve collaboration, and make it a mutual learning experience instead of 
        a struggle.</p>

<section id="">
<p class="pairing-subheading">Ways to tackle</p>

<p>A conversation at the beginning of your pairing session can help
          you to understand differences between your styles, and plan to adapt
          to that. Start your first session with questions like "How do we want
          to work together?", "How do you prefer to pair?". Be aware of how you
          like to work and how you are efficient, but also don't be closed off
          to other approaches - maybe you'll discover something new. </p>

<p>At the end of a day of pairing, do a round of feedback for each
          other. If the idea of giving feedback seems daunting to you, think
          about it more as a mini retrospective. Reflect on how you both felt
          during the pairing session. Were you alert? Were you tired? What made
          you feel comfortable, what not? Did you switch the keyboard often
          enough? Did you achieve your goals? Is there anything you would like
          to try next time? It's good to make this a routine early on, so you have
          practice in giving feedback when something goes wrong. </p>

<p>There are excellent trainings and <a href="https://www.penguinrandomhouse.com/books/331191/difficult-conversations-by-douglas-stone-bruce-patton-and-sheila-heen/9780143118442/">
          books</a> that can help you deal with interpersonal conflicts and
          difficulties, for example on difficult conversations.</p>

<p>Face the challenges as a team and don't leave conflicts to
          individuals. You can do this for example by organising a session on
          pairing in which you discuss how to deal with difficulties together.
          Start the session by collecting the benefits of pairing, so that you
          know what you all want to get out of it. Afterwards collect the
          challenges each individual feels when pairing. Now the group can think
          about which actions might help to improve. You could also collect the
          hot button triggers of the team members: What makes you immediately
          feel uncomfortable when pairing?</p>
</section>
</section>

<section id="InterruptionsByMeetings">
<h3>Interruptions by meetings</h3>

<p>Have you ever had days full of meetings, and you get the impression
        you are not getting anything done? This probably happens in every
        delivery team. Meetings are necessary to discuss, plan and agree on
        things you are going to build, but on the other hand they interrupt the
        flow. When a team practices pair programming the effect of too many
        meetings can get even worse. If each of the persons pairing
        has meetings at different times, the interruptions are multiplied.</p>

<section id="">
<p class="pairing-subheading">Ways to tackle</p>

<p>One approach is to limit the time slots in which meetings happen,
          for example by defining core pairing hours without meetings, or by
          blocking out no-meeting-times with rules like "no meetings after noon".</p>

<p>It is also worth thinking about meeting length and overall amount.
          Which meetings do you really need? What goals do they have and how can
          you improve their quality, for example with proper preparation,
          facilitation, and a clear agenda.</p>

<p>But one thing is for sure: There will always be meetings. So how to
          deal with that as a pair? Check your calendars together at the
          beginning of your pairing session, make sure you have enough time to
          start pairing at all. If you have any meetings consider attending them
          as a pair. Rely on your Product Owner, or other non-pairing team
          members, to keep interruptions away from the team in the core pairing
          hours.</p>
</section>
</section>

<section id="DifferentSkillLevels">
<h3>Different skill levels</h3>

<p>When two people with different experience levels pair on a topic,
        this often leads to false assumptions on how much each of them can
        contribute, or frustrations because of difference in pace.</p>

<section id="">
<p class="pairing-subheading">Ways to tackle</p>

<p>If your pair has more experience on the topic: Don't assume they
          know best. Maybe the need to explain why they are doing things the way they are 
          will bring them new insights. Asking questions on
          the how and why can lead to fruitful discussions and better solutions.
          </p>

<p>If your pair has less experience on the topic: Don't assume they
          cannot contribute much to the solution. You might be stuck wearing
          blinders and a different viewpoint can help you to come to a better
          solution. Also, remember that having to explain a concept is a great
          opportunity to test if you've really understood it and thought it all
          the way through.</p>

<p>It also helps to be aware of different learning stages to
          understand how the learning process from novice to expert works. Dan
          North has described this very nicely in his talk <a href="https://www.youtube.com/watch?v=lvs7VEsQzKY">Patterns of Effective Teams</a>.
          He introduces the <a href="https://apps.dtic.mil/dtic/tr/fulltext/u2/a084551.pdf">Dreyfus Model of Skills
          Acquisition</a> as a way to understand the different stages of learning,
          and what combining them means in the context of pairing.</p>
</section>
</section>

<section id="PowerDynamics">
<h3>Power Dynamics</h3>

<p>Dealing with power dynamics is probably one of the hardest challenges
        in this list. Pair programming does not happen in a space without
        hierarchies. There are formal hierarchies, for example between a manager
        and their report, and informal ones. Examples for informal hierarchies
        are:</p>

<ul>
<li>junior - senior</li>

<li>non-men - men</li>

<li>career changers - folks with a CS degree</li>

<li>People of color - white folks</li>
</ul>

<p>And these are just a few. Power dynamics are fluid and
        intersectional. When two people pair, multiple of those dynamics can be
        in play and overlap. To get an idea of how power imbalance can impact
        pairing, here are a few examples. </p>

<ul>
<li>One person is dominating the pairing session by hogging the keyboard
          and not giving room to their pairing partner.</li>

<li>One person stays in a teaching position and attitude all the
          time.</li>

<li>One person is not listening to the other one, and dismissing their
          suggestions.</li>
</ul>

<p>It sometimes can be subtle to tie these situations back to
        hierarchies, you often just think that you don't get along with each
        other. But the underlying issue is often times influenced by an
        imbalance between the two folks pairing. </p>

<p>Sarah Mei has written an <a href="https://twitter.com/sarahmei/status/991001357455835136">excellent
        series of tweets</a> on the topic and has also given a talk that
        covers <a href="https://www.youtube.com/watch?v=YL-6RCTywbc">power dynamics in agile</a> in
        a more general way.</p>

<section id="">
<p class="pairing-subheading">Ways to tackle</p>

<p>The first step to tackle this is for the person on the upward side
          of the power dynamic to acknowledge and admit to themselves their
          position. Only then can you honestly reflect on interactions you have
          with your pairing partner, and how power dynamics impact them. Try to
          think about your own positionality and situatedness. What can you
          actively do to neutralize power imbalance?</p>

<p>Recognizing these types of differences and adapting our behaviour
          to improve collaboration can be hard. It requires a lot of self
          reflection. There are trainings that can help individuals or teams
          with this, for example "anti-bias" or <a href="https://frameshiftconsulting.com/ally-skills-workshop/">
          ally skills</a> trainings.</p>
</section>
</section>

<section id="PairingWithLotsOfUnknowns">
<h3>Pairing with lots of Unknowns</h3>

<p>When you work on a large topic where both of you don't have an idea
        how to solve a problem, the usual pairing styles often don't work as well. 
        Let's say you need to use a technology for the first time, or try out a new approach or pattern.
        Researching and experimenting together works in some constellations,
        but it can also be frustrating because
        we all have different approaches to figuring out how things work, and we read
        and learn at different paces.</p>

<section id="">
<p class="pairing-subheading">Ways to tackle</p>

<p>When there are lots of unknowns, e.g. you work with a new
          technology, think about doing a <a href="https://en.wikipedia.org/wiki/Spike_(software_development)">
          spike</a>  to explore the topic and learn
          about the technology before you actually start working. Don't forget
          to share your findings with the team, maybe you have a knowledge
          exchange session and draw some diagrams you can put up in the team
          space.</p>

<p>In these situations, remember to take on the mindset of <a href="#PairDevelopment">pair development</a>, as opposed to pair <i>programming</i>. It's okay to split up to do research - maybe after agreeing on the set of questions you need to answer together.</p>
</section>
</section>

<section id="NoTimeForYourself">
<h3>No time for yourself</h3>

<p>We've talked about how being in a constant conversation with each other can be pretty energy draining. Most people also need some time on their own throughout the day. That is especially true
        for more <a href="https://www.ted.com/talks/susan_cain_the_power_of_introverts?language=en">introverted folks</a>.</p>

<p>When working solo, we quite naturally take time to dig into a topic or learn when
        we need to. But that can feel like an interruption in pairing. So how can you take that alone and
        learning time when needed?</p>

<section id="">
<p class="pairing-subheading">Ways to tackle</p>

<p>Again, don't pair 8 hours a day, agree on core coding hours with your team and
          keep it to a maximum of 6 hours per day. Maybe you also want to
          allocate a few hours self learning time.</p>

<p>When a pair feels that they don't have the collective knowledge to
          approach a problem, split up to read up and share back, then continue
          implementation.</p>
</section>
</section>

<section id="RotationsLeadToContextSwitching">
<h3>Rotations lead to context switching</h3>

<p>Knowledge sharing is one of the benefits of pairing, and we have mentioned how
        <a href="#PairRotations">rotations</a> can further increase that effect. On the other hand,
        too may rotations leat to frequent context switching.</p>

<section id="">
<p class="pairing-subheading">Ways to tackle</p>

<p>Find a balance between frequency of rotations and the possibility for
          a new pairing partner to get enough context on the story and
          contribute properly. Don't rotate for the rotation's sake, think about
          if and why it is important to share a certain context, and give it enough time to be effective.</p>
</section>
</section>

<section id="PairingRequiresVulnerability">
<h3>Pairing requires vulnerability </h3>

<blockquote>
<p>To pair requires vulnerability. It means sharing all that you know
          and all that you don't know. This is hard for us. Programmers are
          supposed to be smart, really-crazy-smart. Most people look at what we do
          and say 'I could never do that.' It makes us feel a bit special, gives
          us a sense of pride and pride creates invulnerability.</p>

<p class="quote-attribution">-- <a href="https://diaryofascrummaster.wordpress.com/2013/09/30/the-shame-of-pair-programming/">Tom Howlett</a></p>
</blockquote>

<p>When you pair, it can be hard to show that you don't know something, or feel insecure about a decision. Especially in
        an industry where myths like the <a href="https://www.thoughtworks.com/radar/techniques?blipid=201911057">10x engineer</a> regularly make their rounds, and where we have a tendency
        to <a href="https://blog.aurynn.com/2015/12/16-contempt-culture">judge each other</a> by what languages we use, or what design decisions we took 5 years ago.</p>

<p>Vulnerability is often connected with weakness and in most modern
          cultures the display of strength is the norm. But as the researcher
          Brené Brown has laid out in several talks and books, vulnerability
          is actually a very important ingredient for innovation and change.</p>

<blockquote>
<p>Vulnerability is the birthplace of Innovation, Creativity and
          Change.</p>

<p class="quote-attribution">-- <a href="https://www.youtube.com/watch?v=psN1DORYYV0">Brené Brown</a></p>
</blockquote>

<section id="">
<p class="pairing-subheading">Ways to tackle</p>

<p>Showing vulnerability requires courage and creating an environment
          where people feel safer to show that their vulnerable.
          Again, this is all about building teams where people trust each other
          (regular 1:1s, Feedback, culture where people can ask questions, etc)</p>

<p>Being vulnerable is easier and less risky for people on the team who 
          have more authority, either naturally (e.g. because they are well-respected 
          already), or institutionally (e.g. because they have a title like "Tech 
          Lead"). So it's important that those people start and role model this, 
          making it the norm and therefore safer for others to be vulnerable as 
          well.</p>
</section>
</section>

<section id="ConvincingManagersAndCo-workers">
<h3>Convincing managers and co-workers</h3>

<p>Advocates of pair programming often struggle to convince their managers or their co-workers 
        to make pairing part of a team's daily routine.</p>

<section id="">
<p class="pairing-subheading">Ways to tackle</p>

<p>There is not a simple recipe to persuade others of the efficacy of pair programming. However, 
          a key element should always be to take time to talk about it first, and make sure that everybody 
          has the same understanding (e.g. by reading this article :-) ). Then find a way to try it out, 
          either by starting with one pair who share their experience with the others, or by proposing a 
          team experiment, like "let's pair by default for the next 2 sprints". Make sure to build in 
          opportunities for feedback and retrospection to share what is going well and what you are struggling with.</p>

<p>
          Ultimately, you can't force a practice on people, and it does not work for everybody. You might end up pairing 
          with only a part of the team - at least in the beginning. From our experience the best way to convince people 
          is by having a regular exposure to the practice, experiencing the benefits and fun their team members have while pairing.
        </p>

<p>
          A question that comes up most frequently in this situation is the economics of the practice: Does pairing 
          just cost double the money, and is it ultimately worth extra cost because of the increased quality and team benefits? There 
          are a few studies on the topic, most notably <a href="https://collaboration.csc.ncsu.edu/laurie/Papers/XPSardinia.PDF">this one</a>, that are 
          cited to provide evidence that pairing is worth it. We are wary though of attempts to "scientifically prove" 
          pairing effectiveness. Software development is a process full of change and uncertainty, with a lot of outcome 
          beyond lines of code that is hard to compare and measure, like analysis, testing, or 
          <a href="https://martinfowler.com/articles/is-quality-worth-cost.html">quality</a>. Staunch opponents
          of pairing will always find ways to poke holes into the reproducibility of any "scientific" experiments set up 
          to prove development productivity. In the end, you need to show that it works for YOU - and the only way to do 
          that is to try it in your environment.
        </p>
</section>
</section>
</section>

<section id="ToPairOrNotToPair">
<h2>To pair or not to pair</h2>

<p>Our experience clearly shows that pair programming is a crucial
      practice to create high quality, maintainable software in a sustainable
      way (see <a href="#Benefits">"Benefits"</a>). However, we also 
      don't believe it is helpful to
      approach it dogmatically and <i>always</i> pair. How exactly pair programming 
      can be effective for you, how much of it, and for which tasks, can vary. We've 
      found it useful to set pair programming as the "sensible default" on teams, and 
      then discuss whenever we want to make an exception.</p>

<p>Let's look at a few examples where it's helpful to balance how and when
      you pair.</p>

<section id="BoringTasks">
<h3>Boring Tasks</h3>

<p>Some coding tasks are "boring", e.g. because they are about using
        some well defined boilerplate approach - so maybe you don't need to
        pair? The whole team already knows this type of approach, or it's very
        easy to grasp, so knowledge sharing is not that important? And live code
        review is less useful because the well-established pattern at hand has
        been used successfully in the past? So yes, maybe you don't need to
        pair.</p>

<p>However, always consider that <a href="https://www.martinfowler.com/bliki/PairProgrammingMisconceptions.html">
        rote tasks might be a smell for bad design</a>: Pairing can help you
        find the right abstraction for that boring code. It's also more probable
        to miss things or make cursory errors when your brain goes into "this
        is easy" autopilot.</p>
</section>

<section id="couldIReallyDoThisByMyself">
<h3>"Could I Really Do This By Myself?"</h3>

<p>Pairing has a lot of benefits for programmers who are just starting
        out, because it is an opportunity to learn relatively quickly from a
        more experienced member of the team. However, junior programmers can
        also experience a loss of confidence in their own abilities when
        pairing. "Could I really do this without somebody looking over my
        shoulder?". They also miss out on learning how to figure things out by
        themselves. We all go through moments of frustration and unobserved
        experimentation with debugging and error analysis that ultimately make
        us better programmers. Running into a problem ourselves is often a
        more effective learning experience than somebody telling us that we
        are going to walk into it.</p>

<p>There are a few ways to counteract this. One is to let junior
        programmers work by themselves from time to time, with a mentor who
        regularly checks in and does some code review. Another way is letting
        the more junior programmers on the team pair with each other. They can
        go through finding solutions together, and still dig themselves out of
        rabbit holes faster than if they were coding by themselves. Finally,
        if you are the more experienced coder in a pair, make sure to be in
        the navigator's seat most of the time. Give the driver space to figure
        things out - it's sometimes just a matter of waiting a little bit
        until you hit that next wall together, instead of pointing it out
        beforehand.</p>
</section>

<section id="CodeReviewVs.Pairing">
<h3>Code Review vs. Pairing</h3>

<blockquote>
<p>The advantage of pair programming is its gripping immediacy: it is
          impossible to ignore the reviewer when he or she is sitting right next
          to you.</p>

<p class="quote-attribution">-- <a href="https://blog.codinghorror.com/pair-programming-vs-code-reviews/">Jeff Atwood</a></p>
</blockquote>


<p>Many people see the existence of a code review process as reason
        enough not to need pair programming. We disagree that code reviews are a
        good enough alternative to pairing.</p>

<p>Firstly, there are usually a few dynamics at play that can lead to
        sloppy or superficial code reviews. For example, when coder and reviewer
        rely too much on each other without making that explicit: The coder
        might defer a few little decisions and improvements, thinking that
        problems will be caught in the review. While the reviewer then relies on
        the diligence of the coder, trusting their work and not looking too
        closely at the code. Another dynamic at play is that of the <a href="https://www.behavioraleconomics.com/resources/mini-encyclopedia-of-be/sunk-cost-fallacy/">sunk cost fallacy</a>: We are usually
        reluctant to cause rework for something that the team already invested
        in.</p>

<p>Secondly, a code review process can disrupt the team's flow. Picking
        up a review task requires a context switch for somebody. So the more
        often code reviews occur, the more disruptive they will be for
        reviewers. And they should occur frequently, to ensure continuous
        integration of small changes. So a reviewer can become a bottleneck to
        integrate and deploy, which adds time pressure - again, something that
        leads to potentially less effective reviews.</p>


<p>With <a href="https://martinfowler.com/articles/continuousIntegration.html">Continuous Integration</a>
        (and Delivery), we want to reduce risk by delivering small chunks of
        changes frequently. In its original definition, this means practicing
        <a href="https://paulhammant.com/2013/04/05/what-is-trunk-based-development/">trunk-based development</a>. With
        trunk-based development, delayed code reviews are even less effective,
        because the code changes go into the master branch immediately anyway.
        So pair programming and continuous integration are two practices that go
        hand in hand.</p>

<p>An approach we've seen teams use effectively is to pair by default,
        but use pull requests and code reviews for the exceptional cases when
        somebody has to change production code without pairing. In these setups,
        you should carefully monitor as a team that your pull requests don't
        live for too long, to make sure you still practice continuous
        integration.</p>
</section>
</section>

<section id="ButReallyWhyBother">
<h2>But really, why bother?</h2>

<p>We talked a lot about the benefits of pair programming, but even more
      about its challenges. Pairing requires a lot of different skills to get
      it right, and might even influence other processes in the team. So why
      bother? Is it really worth the hassle?</p>

<p>For a team to be comfortable with and successful at pair programming,
      they will have to work on all the skills helpful to overcome its
      challenges: Concentration and focus, task organisation, time management,
      communication, giving and receiving feedback, empathy, vulnerability - and these
      are actually all skills that help
      immensely to become a well-functioning, collaborative and effective
      team. Pairing gives everybody on the team a chance to work on these
      skills together.</p>


<p>Another factor that is widely talked about today as a success factor
      for effective teams is diversity. Diversity of perspectives, genders,
      backgrounds and skills has proven to improve a team's performance - but
      it often increases friction first. It can even increase some of the
      challenges with pair programming we talked about. For example, one of
      the key ingredients we suggested is showing vulnerability, which is
      especially hard for team members of underrepresented groups.</p>

<p>Consider this headline from Harvard Business Review: <a href="https://hbr.org/2016/09/diverse-teams-feel-less-comfortable-and-thats-why-they-perform-better">"Diverse Teams Feel Less Comfortable - and That's
      Why They Perform Better"</a>. The authors are making the point that
      "Homogeneous teams feel easier - but easy is bad for performance. (...)
      this idea goes against many people's intuitions". To explain, they point
      out a cognitive bias called the fluency heuristic: "We prefer information
      that is more easily processed, and judge it to be more true, or more
      beautiful."</p>

<p>This bias makes us strive for simplicity, which serves us very well
      in a lot of situations in software development. But we don't think it
      serves us well in the case of pair programming. Pairing feels hard – but
      that doesn't necessarily mean it's not good for a team. And most
      importantly, it does not have to stay hard. In <a href="https://www.youtube.com/watch?v=S92vVAEofes">
      this talk</a>, Pia Nilsson describes measures her team at Spotify took
      to get over the uncomfortable friction initially caused by introducing
      practices like pair programming. Among other things, she mentions feedback
      culture, non-violent communication, <a href="https://hbr.org/2017/08/high-performing-teams-need-psychological-safety-heres-how-to-create-it">
      psychological safety</a>, humility, and having a sense of purpose.</p>

<p>Pair programming, extreme programming, and agile software development
      as a whole are all about embracing change. Agile software practitioners
      acknowledge that change is inevitable, so they want to be prepared for
      it.</p>

<p>We suggest that another thing we should embrace and prepare for is
      friction, because it's also inevitable on the way to becoming a highly
      effective, diverse team. By embracing friction we do NOT mean to say,
      "let's just have lots of conflicts and we'll get better". What we mean
      is that teams should equip themselves with the tools necessary to deal
      with friction, and have them in their toolbox by default, not just when
      the team is already having problems. Practice feedback, improve team
      communication, take measures to create a psychologically safe
      environment.</p>

<p>We believe that pair programming is often avoided because it can
      create friction, but we would ask you to give it a chance. If you
      consciously treat it as an improvable skill, and work on getting better
      at it, you will end up with a more resilient team.</p>
</section>
</article>


<hr>

<footer>
  <p>
    <a href="/david/" title="Aller à l’accueil">🏠</a> •
    <a href="/david/log/" title="Accès au flux RSS">🤖</a> •
    <a href="http://larlet.com" title="Go to my English profile" data-instant>🇨🇦</a> •
    <a href="mailto:david%40larlet.fr" title="Envoyer un courriel">📮</a> •
    <abbr title="Hébergeur : Alwaysdata, 62 rue Tiquetonne 75002 Paris, +33184162340">🧚</abbr>
  </p>
</footer>
<script src="/static/david/js/instantpage-3.0.0.min.js" type="module" defer></script>
</body>
</html>