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#52 XP – Speaking the same language


A few months ago I finished my 17 months long stay in Singapore. It was an amazing time during which I met brilliant people, sweated a lot in tropical weather and worked on a messaging application for iOS.

The company I worked for used eXtreme Programming methodologies for software development. We used XP every business day for 8 hours. Because of that TDD became a habit, lack of companion when programming became a burden, and the legacy code became no fear to me. Let me tell you why XP is useful and why pair programming is helpful when working on a project.

eXtreme Programming

We live in times in which everything changes rapidly. Not longer than 5 years ago (June 2014) majority of production code for iOS apps was written in Objective-C only, whereas today many companies try to minimise Objective-C code in favour of Swift. Not only technology and tools we use evolve and change, but also business requirements for our apps. Companies that can adapt to changing conditions and can develop quality software in an agile way can survive and ship valuable products.

Extreme programming (XP) is a methodology for creating software of high quality in a responsive way to changing requirements. It values a set of good practices and pushes using them to their limits:

  • Unit tests are great, they verify that app components behave in a desired way. XP uses TDD approach – tests are written before production code.
  • Integration & Deployment can be done manually – code is tested and build locally on our computer and archived to be deployed to Appstore. With XP it is done automatically and continuously on integration servers after every push to the repository.
  • Code review catches bugs and improves the design and quality of our code. XP pushes it to extremes too – pair programming is used to conduct continuous code review.

Pair programming = 2 people doing one person’s job

I heard about this wrong perception that pair programming is 2 people doing one person’s job. What actually is pair programming?


Graphic - workstation with 2 screens, 2 mice and 2 keyboards
Graphic – workstation with 2 screens, 2 mice and 2 keyboards

Two people in front of 2 screens, 2 keyboards and 2 mice connected to a single computer working on the same thing. Pair programming is mainly a discussion about how to solve a certain problem. It leads to coming up with a better design and doing it right the first time. Pair members get instant feedback on their ideas thanks to the continuous conversation about the task at hand and its implementation.

Getting quality fast

Have you ever had this feeling that it takes ages to merge your PR (Pull Request) to the main development branch? You implement your new functionality, push changes to a remote branch, create a PR and then you wait… and wait… and finally somebody reviews your changes, leaves some comments. You apply them to your work, and then you wait for feedback again… With continues code review a.k.a. pair programming you get feedback right away. It’s a faster way of working and getting better quality of code. You can push directly to the master because the code you worked on with your pair is considered reviewed. Of course, crucial parts can still go through PR if you need another opinion. Be agile and change approach if needed 🙃!

Ramping up and spreading knowledge

We had these new guys joining our development team. If they had to dive into our legacy codebase solo, they wouldn’t have become effective quickly. Pairing allowed them to ramp up fast. The project’s legacy codebase was extremely complicated, old and lacking unit tests for crucial parts. When they worked with experienced peers they could learn about the project from them. Good practices were spread right away and a knowledge about the project was shared on the job.

Some new teammates didn’t have experience in Objective-C, nor in TDD. If you learnt Objective-C you know how difficult it probably was for you at the beginning and how different it is from Swift. If you practice TDD, you understand that it demands perseverance and skill in unit testing. Our teammates could learn from the experience of other peers thanks to pair programming.

It would be great if knowledge of application components was distributed evenly, i.e. every team member would feel comfortable and capable of working on any part of the app. You can achieve that by rotating pairs. At every daily standup, people would tell what they planned to work on. Then peers agree on what and whom they want to work with. And hey – not every task makes sense to be done in pair programming mode 😉.

Pair rotation teaches the skill of adaptation to new tasks easily. One person from the initial pair working on the task stays with it till it’s finished and the other person can step back from the task and work with someone else on another task. It also spreads the knowledge and gives fresh look and opinion on solutions when new people joined to pair with you.

Distraction free

Nowadays it’s extremely easy to get distracted. Phone buzzing with notifications, e-mail needs to be answered, new blog post on “XYZ” needs to be read. After an hour you can find yourself still not having started the work…

While you’re pairing, you’re actively involved in the task. You discuss the code and you don’t answer sms or watch YouTube.

A few days ago I was thinking through how to solve a certain problem in the application. Then my colleague waved at me and ask some question about the app. I needed to navigate to a different part of the project and talk about it for a while. When we finished I needed a few minutes to get back on track…

When programmers are pairing people see that they are actively involved in their work. People will wait for the appropriate moment to approach them to discuss things through. What’s also great about pairing is that when somebody approaches the pair one member can handle the interruption while another will stay focused and work on the task.

Rewarding way to work

Pair programming is just fun and rewarding way to work. You have a mutual goal and pursue with your pair to achieve it. This pursuit is accompanied with a lot of laughter and it allows you to get to know your colleagues more and to make this special connection with them.

Glimpse of an eye

When you do pair programming you never end up in situations when people start arguing about who will use the keyboard. Of course you have two sets of them, but usually only one is used at a time. Pair agrees on the way they want to work. It can be that one person writes the test and the other implements the code. It can be communicated verbally that one wants to write code – “Hey, let me do it!” 😉.

But there is more than that. When you practice pair programming constantly for some period you start understanding non-verbal communication.

When you type on a keyboard and you notice by a glimpse of an eye a subtle movement of your peer’s hand approaching their keyboard, you immediately know that it means that they want to start typing and to introduce their concepts so you can react to this non-verbal language right away. You understand your pair with no words.

Speaking the same language

Sometimes even if we speak the same language we don’t understand each other. Language can mean many aspects – Objective-C/Swift, Polish/English, body language, language of shared experienced.

I spent 17 months where Chinese is one of spoken languages and my friends taught me some of it:


Wǒ bù shuō nǐ shuō de yǔyán in Chinese means I don’t speak the same language that you speak.

Pair programming allowed me to learn non-verbal language, to understand people coming from different backgrounds and cultures. It allowed me to “speakthe same language, share my experience and learn a lot from others.


I can’t sum up pair programming by not quoting my previous manager. It’s just a rewarding way to work. You have a lot of fun while working with others. It’s an exciting adventure which gives new experience. With pair programming you get better code and higher quality much faster than in a standard approach to software development.

pair programming
wait ages for PR review instant feedback
slow solo discover fast developer ramp up
distraction threat focus on the job


If you want go fast, go alone.
If you want to go further, go together.

African proverb


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