How to quickly ramp up on new codebases

Joining a new team is intimidating. There is always much to learn - new people, new processes, and a new code base.

Ramping up on your new team’s code base is difficult, but knowing how to work effectively in it is crucial to your success. So, how do you do it quickly?

My mid- and early senior developer years were intense. Due to a mix of reorgs and personal interests, I found myself on a new team every year or so. As a result, I had to learn new codebases in quick succession. They included .NET System.Xml, OData, Entity Framework, Entity Framework Designer, Core, and the Alexa mobile app, and most of them were over one hundred thousand lines.

The first couple of transitions were slow and overwhelming. But they helped me develop a strategy I used later to quickly get up to speed on new codebases.

Get your hands dirty ASAP

The sooner you start working actively with the code base, the sooner you will get productive. Reading documentation can be helpful, but nothing can replace the hands-on experience.

When I joined Amazon, I asked my manager to assign me a simple bug to fix on my first day. Even though the fix amounted to a single line of code, it took me a few days to send it for review. It might seem long, but this quest was not about fixing the bug. Rather, it was about forcing myself to set up my development environment, learn how to build and run the code, write unit tests, and debug our product.

Review code

Each team has its way of letting members know there is a new PR (Pull Request) for review. It could be email, chat, or review tool notifications. Whatever it is, subscribe to this channel and start reviewing PRs. You won’t understand much initially, but you may still catch some bugs (e.g., off-by-one errors). More importantly, these reviews will allow you to