Our Approach to Mob Programming

Our teams at ClassDojo have the freedom to choose how they want to work. Many of our teams have started spending a few hours each day mobbing because we've found it to be an effective form of collaboration. Here's how we do it!

What is Mob Programming?

Mob programming is similar to pair programming, but with more than two people working together. One person, the driver, does the actual typing but everyone is involved in the problem solving. Mob programming is often defined as “All the brilliant minds working on the same thing, at the same time, in the same space, and at the same computer.” We don’t follow the strict definition of mobbing, especially since we are a fully remote team, but we are continuously iterating on an approach that works for us.

Why do we mob?

Woody Zuill has a great writeup about how a whole range of issues just faded away once his teams started mobbing, including fading communication problems and decision making problems, without trying to address those issues directly. We’ve found similar benefits, and I’ll call out just a few:

Focus

When the team is working together on a single task, it means we’re focused on the top priority for our team. Although it may sound more productive to have multiple engineers working in parallel on separate tasks, that often means that the top priority is delayed when waiting for answers to questions. Having the whole team focused on the same thing greatly decreases the amount of context switching we need to do.

Knowledge Sharing

Without mobbing, it’s easy to develop silos of knowledge as individuals become experts in specific areas. Others might gain context through code reviews or knowledge sharing meetings. However, when the whole team works together on a piece of code, it almost eliminates the need for code reviews since all the reviewers were involved in writing it, and everyone already has shared knowledge. Mobbing is also really useful for onboarding new teammates and getting them up to speed.

Quality

More time is spent debugging and refactoring code than writing it. If you mob, you have more eyes on the code while it’s being written, rather than during code review or later when it needs to be updated or refactored. You increase the quality of your output, and that quality increase leads to long-term speed.

Collaboration

Especially with a fully remote engineering team, it can be isolating to only work on individual tasks. There is also the challenge of communication and having to wait for answers to blocking questions. By having everyone attend the mob, we eliminate that waiting time. Questions can be answered immediately and decisions are made as a group.

What does remote mobbing look like at ClassDojo?

Who: Most often, we have all the engineers of the same function (e.g. all the full-stack engineers) on a team join a mob. Depending on the task it can be helpful to have other functions like client engineers or product managers join as well, to quickly answer questions and unblock. The group will naturally include engineers of varying skill levels, which is a good thing! We rotate drivers often, but like to have the less experienced engineers drive as it keeps them engaged and learning.

When: This depends on the team’s preference and availability as well as the nature of the task, but we may schedule mobbing time for anywhere from an hour to almost the entire day, most days of the week. It’s important to block the same time off on each person’s calendar and protect that time from other meetings. During longer sessions, we set a timer to remind ourselves to take breaks often. We generally take a 10-15 minute break after every 45 minutes of focused mobbing.

What: We pick one task to focus on, and it should be the highest priority task for the team. It’s easy to get derailed by PRs that need reviewing, bugs that get reported, questions on slack, etc, but we make a conscious effort to avoid starting anything new until we finish the current task. The one exception we have is for P-now bugs, which we drop everything else for.

How: No special tools or complex setup required! We simply hop on a Zoom call and the driver shares their screen. If we’re coding, the driver will use their own IDE and when it’s time to switch drivers, the driver pushes the changes to a branch so the next driver can pull the latest. There are tools for collaborative coding, but we’ve found that they don’t offer much benefit over simply having someone share their screen. If we’re in a design phase, we often use Miro as a collaborative whiteboard.

As with everything we do, we have frequent retrospectives to reflect on what’s going well and what could be improved with how we mob, and we are open to trying new ideas. If you have any thoughts, we’d love to hear from you!