Called Mad — called

11 Aug 2026 / 7 min

Depends is dependency injection.But it isn't dependency inversion (or DIP) within SOLID.

Two patterns with similar names: one interface I kept, one I deleted, and the point where FastAPI's own mechanism stops being enough.

#architecture #fastapi #python

11 Aug 2026 / 3 min

The Protocol I wrote and then deleted

An interface with one implementation describes that implementation twice. The one I kept exists for a different reason entirely.

#architecture #python

11 Aug 2026 / 3 min

The refusal said the same thing. It did not take the same time!

Unknown address and wrong password returned an identical message — and very different response times, because short-circuiting skipped the hash.

#security #python

11 Aug 2026 / 3 min

The JWT claim that lost a fraction of a second and it kills all auth

A password change should end older sessions. It sometimes ended the new one too, because PyJWT truncates a datetime claim to whole seconds. And you can never claim your own JWT!

#jwt #security #python

11 Aug 2026 / 3 min

A circular import told me where I should start my app

Suddenly, my app crashed. It stopped importing. The first fix was to break the cycle — and then it was to notice that pagination had never belonged next to posts. How tragic it was...

#architecture #python