I wouldn't call it a "debugger", but plenty of people run an instrumentation agent like New Relic or AppDynamics that records tracing information on their production web services with little or even zero modification to their application code.
> I used to use NewRelic APM with Go and it required additional code to instrument.
I'm not surprised, Go's runtime is pretty limited. But for e.g. Java if you're using a well-known/"standard" framework you can just flick the switch and it'll give you a lot of good useful information - additional manual instrumentation usually helps, but the level of instrumentation without it is useful.