Question: How best to find slow parts of a stream?

All it takes is one link for a chain to be weak, I'm curious if anyone has any good ways to locate these links for optimization purposes.

The issue names no file, test, or entry point and asks for general guidance on locating slow links in a stream chain. Start by identifying whether the project intends to add profiling support or document an existing approach; completion criteria are not defined in the issue.

Written by the indexing model from the issue text.