Anything where you get crash reports back from the field. It is very valuable to be able to read assembly code and map registers to their purpose, and then perhaps back to the source code that generated the assembly. Debuginfo will sometimes give you some of that, but is unreliable, incomplete, and can be hard to match up to the stripped binary you're looking at. Recognizing values that are likely to be stack vs uninitialized or poisoned vs corrupted vs nullptr or offsets to nullptr... it can turn a crash report from absolutely cryptic into something that gives you the lead you need.
(Also, if you are dealing with something with mass deployment, it's good to recognize the single-bit flips that are hallmarks of bad RAM. But don't assume too much; bit flips are also the sign of bit flag manipulations.)
(Also, if you are dealing with something with mass deployment, it's good to recognize the single-bit flips that are hallmarks of bad RAM. But don't assume too much; bit flips are also the sign of bit flag manipulations.)