We have had luck using the py-spy tool, which runs your Python script in a separate process and samples it, to profile our tests to get a rough sense of how long things take:
# Run with sudo so it can inspect the subprocess
sudo py-spy record \
# Save as speedscope so we can load in the browser
--format speedscope \
# Group by function name, instead of line number
--function \
# Increase the sampling rate from 100 to 200 times per second
-r 200 -- pytest tests/After creating your trace, you can load it in Speedscope.
In this example, we are inspecting calls to transform.
We see that it cumulatively takes up 12% of total time and that most of the
time inside of it is spent visiting imports, as well as committing to the DB:
