Python 3.8 introduced a built-in module for entrypoint discovery https://docs.python.org/3.8/library/importlib.metadata.html with a backport for <3.8 and 2.7 here: https://importlib-metadata.readthedocs.io/en/latest/

While there's nothing wrong with pkg_resources other than we need reentry to make it scale, we should do a test with importlib.metadata to see whether it would be fast enough for us without reentry.

Release notes from pluggy (pytest) and tox suggest that it performs better than setuptools pkg_resources.