How quickly can you understand someone else's code?

The speed of understanding someone else's code depends on several factors: the quality of documentation, coding style, presence of comments, and project architecture.

To quickly get a grasp, I usually:

• Study the README and documentation to understand the purpose and overall structure.
• Review the main classes and their interactions.
• Use a debugger or logs to understand the flow of execution.
• Look for tests that show examples of code usage.

Experience and knowledge of the technologies used also greatly speed up the process. On average, for a small module, it can take a few hours to understand, while for larger systems, it can take from several days to weeks.