Having recently had the pleasure of having to debug JIT-compiled code with an ABI mismatch, I can't overstate how useful `rr` (https://github.com/mozilla/rr) can be to debug assembly. The ability to `rsi` e.g. reverse step instruction is very powerful.

One tool that I started exploring is https://pernos.co/, the ability to do dataflow analysis is super cool. Let's you easily answer the question "How did this value get into this register".