What’s the best way to get comfortable reading unfamiliar codebases?

Start by finding the entry point or the part of the application you can observe directly. Depending on the language, that might be a main function, an entry file, a command-line handler, or a framework-specific startup file. Documentation and the README are worth checking first. From there, follow one concrete piece of behavior—such as a screen, API endpoint, or command—instead of trying to understand every file at once. Trace its calls outward and jump into functions only when you need to know what they do. This gives you a useful map without turning the whole codebase into a giant reading assignment.

This really is a skill that improves through repetition. Pick small, reasonably maintained projects and choose one feature to follow from input to output. Afterward, summarize the flow in your own words and try making a small change. You’ll gradually get better at recognizing conventions, locating entry points, and deciding which details can safely be ignored.

AI can be helpful for creating a high-level outline, explaining unfamiliar functions, or describing how modules connect, especially in a large project. Treat its answers as suggestions rather than facts, though. It can miss version differences, misunderstand assumptions, or confidently invent details. Verify important explanations by checking the actual code and the language or framework documentation. Keeping short notes or drawing a simple dependency map can also make the structure easier to remember.

You usually don’t need to understand the entire project. First learn what each important function is responsible for and how the pieces interact; only study the implementation details when they matter to the feature or bug you’re working on. When debugging, run a test or reproduce the problem and trace the execution until the behavior stops matching your expectations. That gives you a focused path through the code and is much easier than reading everything from top to bottom.