[Developer] My app/function is running slow, I want to understand why

[mdemirhan]

Quote from @evankanderson:

I think there are two cases here, I presume based on the comments that this is 1:

1. My function is being slow because one or more backends have gotten slower (tracing + backend latency graphs)
2. My function is being slow because the code is inefficient (e.g. poor use of regular expression leading to lots of backtracking).

In this epic, we will only cover 1. Profiling is not covered as part of this work.