TDD can be a great way to debug, particularly if it takes a lot of effort to get your running app into the state where the bug occurs. Write a cucumber scenario

TDD can be a great way to debug, particularly if it takes a lot of effort to get your running app into the state where the bug occurs. Write a cucumber scenario that sets up the conditions where you think the bug occurs and tweak until you're able to replicate. If you know when a bug occurred you can take a look at your logs and then use those to construct your bug scenario in cucumber. Once you're able to replicate in cucumber it's usually far faster to fix because your test cycles are much shorter (automatic vs having to put the running app in the correct state each time).