Debug and extend a Python codebase by adding an async exponential retry mechanism with timeouts and backoff so failures are retried until success.

Focus on understanding the existing Python codebase and identifying areas where the retry mechanism can be integrated. Pay attention to the structure of the asynchronous functions and how they handle errors. When implementing the exponential backoff, ensure that you clearly define the retry logic, including the maximum number of retries and the timeout duration. Be prepared to explain your design choices, such as how you handle different types of exceptions and the implications of using async/await in your implementation. Lastly, consider edge cases and how your solution can be tested effectively.