Notes on backend engineering, mostly things I had to figure out at work.https://juarezlustosa.comhttps://juarezlustosa.com/writing/slow-endpoint-not-always-n-plus-onehttps://juarezlustosa.com/writing/slow-endpoint-not-always-n-plus-oneHow to distinguish repeated Rails queries from an expensive PostgreSQL query plan, using a fictional example and a measurement-driven investigation.Thu, 22 Oct 2026 00:00:00 GMT