https://cs.lozic.me/areas/software-engineering/Recent content in Software-Engineering on CS TheoremsHugoen-usFri, 23 Oct 2026 12:00:00 +0200https://cs.lozic.me/posts/t089-conways-law/Fri, 23 Oct 2026 12:00:00 +0200https://cs.lozic.me/posts/t089-conways-law/<h2 id="symptom">Symptom</h2> <p>The service has four layers. Nobody designed four layers. There were four teams.</p> <p>Or the version that arrives in a postmortem: the outage happened at the boundary between two services, in the retry logic, because each side assumed the other owned the deduplication. Both teams were right about their own component and neither had ever been in a room with the other.</p>https://cs.lozic.me/posts/t091-hyrums-law-and-postels-principle/Fri, 11 Sep 2026 12:00:00 +0200https://cs.lozic.me/posts/t091-hyrums-law-and-postels-principle/<h2 id="symptom">Symptom</h2> <p>You fix a typo in an error message. Four days later a customer escalates: their alerting pipeline greps for the old string and has gone quiet.</p> <p>Or you make a function faster, and a test suite that had been green for two years starts failing intermittently — not because the function is wrong, but because it used to be slow enough to hide a race.</p>