Distributed-Systems

Retiring snapshot-per-write for an event-fed read model TL;DR: Shakespeare succinctly describes what will follow, but our history storage mechanism was worse than O(N) — we were writing a whole copy of everything on every change. We moved to using events and an event-driven architecture. This is very much appreciated by our DB. Event-driven systems are an aggregation of the past — what’s past, is prologue! (The Tempest, Act II) I discuss this topic very briefly here as well (2018 video): https://youtu.be/-VJ6FtTS8zg ...

When Sara is taking her exam, the last thing she has on her mind is whether clicking “submit” will actually work. The exam ends: in the last two minutes of the window, most of the class hits submit at the same time. It’s not only the class — these are central exams, everyone in the country is submitting at the same time. When the system shows “Submitted”, this is a promise to Sara that her exam is now safely stored with it and she doesn’t need to worry. ...