Built an async domain & SSL checker with FastAPI, looking for architectural tips

I recently built a small side project using FastAPI to run parallel checks on domains (DNS records, SSL cert status, Wayback data).

Async setup helped a lot with multi-endpoint response times, but I'm trying to fine-tune how I handle slow DNS timeouts when hitting multiple targets at once.

Current stack is pretty simple: FastAPI, React, and Redis for caching.

How do you guys usually structure timeouts and retries for external async calls in production? Any patterns or libraries you swear by?