We have a website that’s been susceptible to a few code conflicts in the past. That’s alright, because we have regular backups in place. However, we do debugging, but I feel we can do better with the debugging aspect. Ideally, we outsource it to another company.
We went through this guide about how to prevent websites from crashing, and have potentially covered all major aspects.
There are a million and one reasons why something might crash.
It could be logic errors, it could be sloppy programming, it could be timeouts (php runtime, webserver), and it could be webserver related (process timeouts, out of memory, incorrect configuration).
Without details of these conflicrs or crashes, its guesswork.
Like with all other things, you need people with the correct experience to address such issues.