Programming with the mob – An offer you can’t refuse

/ 12 Jun, 2018

There is a team in San Diego that started coding together with all the team members working on one computer. It sounds a bit crazy. So why did they do this? It grew out of the desire to maximize learning, sharing knowledge and innovation; That and a lot of experimentation.

Management didn’t care about the chosen approach; the only thing that counted were the results and those looked good. The team got more work done with fewer bugs in production by writing solid code. They coined it Mob Programming. After reading this article you will know the foundational ideas behind the concept, its advantages and how to get started to make this work. We think it is a valuable addition to adopting a DevOps culture and way of working.

What is mob programming?

You could regard Mob Programming as pair programming on steroids. Pair programming has its origins in the Extreme Programming philosophy: it encourages two developers working behind the same computer, working on the same code. While doing so, they both have a clear role. One is behind the keyboard writing the code while the other verifies what is written and is thinking ahead about the next steps to take. They regularly exchange these roles.

Mob programming takes this discipline a step further. The whole team works on the same thing, at the same time, in the same space, and at the same computer. So, you could compare it to pair-programming, but collaboration now includes the entire team instead of two persons. In the end, all the work is about delivering code to create done software.

Definition of Mob Programming

Figure 1: Definition of Mob Programming (source: Mob Programming, Woody Zuill)


Foundational ideas

The advantages mentioned are key ingredients to culture and sharing, which are elements of the CALMS (Culture, Automation, Lean, Measurement and Sharing) principles of DevOps. Moreover, the foundational ideas behind Mob Programming are in line with the DevOps philosophy:

The people doing the work can best figure out how to do that work.

One of the characteristics of a DevOps team is autonomy. In order to collaborate effectively, the team members need to be able to make decisions and apply changes without complicated decision-making processes. This requires trust, changing the way risk is managed, and creating an environment that is free of a fear of failure, i.e. an environment that encourages fast learning. Mob programming sets the stage for this environment under the condition that management gives the team the autonomy and aligns teams by setting shared goals.

Alignment enables autonomy

Figure 2: Alignment enables autonomy (source: Henrik Kniberg)

We can get a lot of benefit out of studying and practicing together

Mob Programming promotes sharing of knowledge between people and providing each other with feedback, with the intention to continuously improve. Another important value that is accomplished is collective ownership, as opposed to individual ownership of work. Instead of relying on everyone on the team knowing everything, which will never happen, it’s great for the team to know everything as a group. If the team feels a sense of collective ownership this group approach will work.

Pay attention to what’s working, and look for ways to “Turn up the good”

A continuous improvement mindset is a key DevOps soft skill. One out of three improvement ideas will be worth holding on to. The other two will be discarded. Finding out in which category an idea falls is the trick and is done by executing Plan, Do, Check and Act cycles. Mob programming will help in achieving improvements by means of working as a team and have an active discussion about it. The reason for this is that any impediments immediately affect the team when working together. So, these topics will need to be discussed and solved on the spot for the team to be able to proceed. This is something that would not easily be done without this type of collaboration.

Getting good at getting good results from retrospectives is important

As with the previous foundational idea, the reflection by the team on the way collaboration is done and how work is being delivered, is a daily, continuously occurring feedback loop. Since the team is constantly together they optimize the opportunity to act on any issues that may occur while they work together. The entire team understands the context of the possible improvement action, they were all present, and it allows the team to act immediately. This fits well with the concept of left-shifting, bringing the opportunity for feedback and improvements forward. If the team is practicing Scrum, it also ensures that the retrospective can be used for tackling larger topics.

Driver-navigator model

The main work of programming is “thinking, describing, discussing, and steering” what we are developing. The Navigators are doing this part while the Driver is doing the translation or transcription of the ideas into code. The driver role is rotated at frequent intervals.

Driver-Navigator collaboration pattern

Figure 3: Driver-Navigator collaboration pattern (source:, Woody Zuill)

When the team grows in experience and maturity, a mobber may will learn to take on one or more (temporary) roles (see cross ref). For example, one may act as a Researcher who and quickly collects information during the development process in order to support the navigator. Or Automationists who focus on options for automating repetitive tasks. If the Driver needs to implement a certain design pattern but doesn’t know how to implement it from the top of his head, the researcher could go and find out on a separate laptop, and then take over as navigator. For more information on these roles, have a look at the Mob Programming Role Playing Game on Github.

Figure 4: Game icons CC-BY 3.0 Delapouite; CC-BY-SA-NC 2015 by Willem Larsen
Powered by the Apocalypse – thanks to BigBadCon 2016 for inspiration


Advantages for a DevOps transformation

Several advantages can be mentioned that all support and speed up your DevOps transformation.

Strengthens Lean thinking

Mob programming brings a lot of focus to the work. The whole team is working collectively on the same thing, expediting the delivery and working towards single piece flow. The ruthless focus removes the need for branching and merging, and other practices that silently consume a lot of time or add overhead in order to facilitate people working in parallel.

Encourages sharing and changing the culture

The culture of sharing, by exchanging knowledge, adopting continuous learning and breaking down barriers by forming cohesive teams, is implicitly carried out. Focusing on delivering the same piece of code makes everybody learn simultaneously about the delivery process and the way a feature is implemented. This strengthens the software craftsmanship culture that is required to excel. Team members learn about things that are out of their comfort zone or specialism. This will lead to building up cross-functional, or T-shaped, team member profiles. If an impediment pops-up it will be discussed immediately (and removed if possible), because it is out-in-the-open and the whole team suffers from it at that very moment. Working together on the same goal gives a shared purpose and strengthens team cohesion, leading to a culture of trust. Last but not least, these are important ingredients for employee and job satisfaction. Altogether this is fostering the DevOps culture.

Increases productivity and quality

Critics say that this way of software development will be slower, and will take more time than working in a more traditional way. However, research has proven that peer-review and code-inspection is one of the most powerful ways of detecting bugs early. You are shifting bug detection to the left of the software delivery process. This could be even more powerful than automatic testing. Shifting left increases productivity and quality, because early detection leads to less rework.

When you also take into account the time that you need to achieve sharing and changing culture when everyone works in a traditional way, there is no reason to assume that Mob Programming may be less efficient than any another approach.

Basic workspace setup to get started

Figure 5: Basic workspace setup to get start (source: Mob Programming, Woody Zuill)

Small experiments with Mob Programming

In the Professional Scrum Developer course we always touch on pair programming. In certain cases the class benefits from experiencing mob programming and we might introduce the concept after the first sprint.

Usually the first experience with Mob Programming is pretty close to total chaos. Everyone needs to understand their role. There is no agreement on what is and what isn’t socially acceptable behavior and often it causes all kinds of hidden issues to surface. This initial experience can feel frustrating or unproductive. A short retrospective at the end of the experience can help bring these frustrations to the forefront and can help remove them. Often these frustrations are happening in the team in their normal way of working, but they’re never bad enough to discuss and resolve them.

Examples of issues surfacing after one hour of Mob Programming:

  • Coding styles between team members are quite different, making it hard to switch driver positions; normally this isn’t an issue as developers would own the code from start to finish.
  • Getting used to giving and receiving feedback. Many teams practice code reviews after a significant portion of the work is done. This reviews the end-product, but not the creative process that led to that result. Pair programming already greatly increases the amount of feedback, and thus the opportunity to learn. With Mob Programming the number of eyes and insights is multiplied even further. People need a safe environment in which they can deal with what may feel like working under a magnifying glass.

At the same time a number of things were very helpful. One hour of working this way led to new insights, which were turned into improvements that would otherwise be unknown:

  • Getting used to giving and receiving feedback. Many teams practice code reviews after a significant portion of the work is done. This reviews the end-product, but not the creative process that led to that result. Pair programming already greatly increases the amount of feedback, and thus the opportunity to learn. With Mob Programming the number of eyes and insights is multiplied even further. People need a safe environment in which they can deal with what may feel like working under a magnifying glass.
  • Because the entire team was working on the same code, no time was spent on merging code. In the previous exercise the team had lost precious time trying to get two features to cooperate properly.
  • Many tips and tricks were shared. Short-cut keys to common actions, alternative solutions for code structures, and tips for better test-ability were shared.
  • Everyone felt comfortable maintaining or having to bugfix the code they had created together.
  • There was far less need for coordination and status sharing. While they still practiced a daily scrum, it focused immediately on the impact, on the goal and other higher-level concerns. No sharing of minute details and progress.

At the end the team felt that working this way would probably cause them to be dead tired before lunch; and that they’d deliver a lot more than they are currently used to.

Getting Started

When asked how to get a team motivated to start Mob Programming, Woody Zuill answered that the goal should not be to do Mob Programming. That they had never set out to do Mob Programming. They wanted to maximize their learning, knowledge sharing and innovation. By ruthlessly striving to achieve these goals through endless experimentation, their way of working eventually led to Mob programming as we know it now. His advice was: If you want people to do Mob Programming, get them sold on the goal. Then again: Who wouldn’t want to work in an innovative environment where everyone is helping each other learn and where you can experiment safely?

Like many other practices and techniques, it’s hard to accept that when you start, you may not get all of the promised benefits immediately. As a team you may need to get together much more than in the past. Issues will surface and you may need help from a skilled facilitator to get through the first hurdles.

To get started you will need:

  • A team that wants to try!
  • A big screen or projector
  • A workstation or laptop to work on
  • One or more keyboards and mice (people have their preferences)
  • A flipchart or whiteboard
  • A goal
  • The safety to try new things.


We challenge you

Applying Mob Programming can speed up your DevOps adoption process. It encourages sharing and makes you adopt your culture on the spot. You can choose to apply it rigorously with an Extreme Programming mindset, but if this is too ambitious or a step too far, you can also do small experiments. Working like this for a few hours, like we did in training, will already give you a lot of insights. We would like to challenge you to have the courage to start experimenting and we look forward to hearing your thoughts.



This article is part of our latest magazine; XPRT.#6   Download it here or get your free copy.