Most backend developers focus on writing new code, but a significant portion of the job involves reading existing codebases. Large systems can feel overwhelming, yet learning to navigate them is what separates competent developers from exceptional ones. The key is to approach the code as a map, not a book, starting with the big picture before diving into details.

Effective navigation begins by identifying main entry points like API routes, controllers, and background workers. Instead of reading randomly, trace a single request end-to-end—such as a GET /users/{id} call—from controller to database. This reveals the system's data flow and provides crucial context for understanding other parts, making the architecture less abstract and more tangible.

Leverage structural clues: folder organization (/controllers, /services, /repositories) acts as documentation, showing where logic and data access live. Use tools like IDE "go to definition" for efficient exploration and let tests and production logs reveal intended behavior and real-world edge cases. Accepting initial confusion is normal; clarity emerges through layered learning and practical changes.