tottime = 0 doesn’t mean fast

Sun, 05 Apr 2026 00:00:00 +0000

Adam Johnson released a new library recently called profiling-explorer. A browser-based interface for .pstats files, the binary output that cProfile writes to disk when you profile Python code. Fancy and friendly UI, kind of tool that makes a familiar workflow suddenly feel less like archaeology.

Looking at it triggered a question that had nothing to do with the tool itself. What’s actually in there the .pstats files? How it gets produced. What it means when cumtime on a function is 20 times larger than tottime. The tool was the rock. The investigation was the wave.

What fork() actually copies and how it impact your celery service

Sat, 28 Mar 2026 00:00:00 +0000

Shallow changes can have consequences at the bottom of the ocean. This post is an account of something that happened to me recently, and the story is still open. The services are stable, the revert held, and a pull request is sitting there waiting for the team to review. The proposed solution makes sense on paper. Whether it fully solves the problem in practice is something we’ll only know after thorough testing in staging next week.

Python on Daniel's Tech Blog

tottime = 0 doesn’t mean fast

What fork() actually copies and how it impact your celery service