Notes on software engineering and systems.https://blog.heidiks.com/https://blog.heidiks.com/posts/return-of-the-3-letter-acronyms/https://blog.heidiks.com/posts/return-of-the-3-letter-acronyms/TDD, BDD, DDD, SDD never left — AI just removed the friction that made them too expensive for most teams.Mon, 20 Apr 2026 15:00:00 GMT