What's the best way to become familiar with a large codebase? [closed]

Solution 1:

Start with some small task if possible, debug the code around your problem. Stepping through code in debug mode is the easiest way to learn how something works.

Solution 2:

Another option is to write tests for the features you're interested in. Setting up the test harness is a good way of establishing what dependencies the system has and where its state resides. Each test starts with an assertion about the way you think the system should work. If it turns out to work that way, you've achieved something and you've got some working sample code to reproduce it. If it doesn't work that way, you've got a puzzle to solve and a line of enquiry to follow.

Solution 3:

One thing that I usually suggest to people that has not yet been mentioned is that it is important to become a competent user of the existing code base before you can be a developer. When new developers come into our large software project, I suggest that they spend time becoming expert users before diving in trying to work on the code.

Maybe that's obvious, but I have seen a lot of people try to jump into the code too quickly because they are eager to start making progress.