If you use nginx or similar at your edge, wrap all calls out to other services and dbs with a function that logs duration to a header. Then you can swiftly identify *any* source of latency or errors using only nginx/access.log. honeycomb.io/blog/tell-me-m…
You'll want to feed it into a tool that lets you slice&dice; you can set this up on @honeycombio free tier in <15 min.
How many hours have you wasted trying to find where the errors are coming from, or debugging the wrong service?
(At honeycomb, of course, we don't have this problem 😉)