The Database Bottleneck

<blockquote> <p>The pager went off at 2:14 AM.</p> </blockquote> <p>If you’ve spent any time operating distributed systems, you know that sound. It doesn’t just wake you up; it

<p>Hello, I'm Tuan.</p> <p>When backend engineers encounter a slow query, the first instinct is often something like:</p> <blockquote> <p>"Check the WHERE and ORDER BY, then just

<p>Most slow PostgreSQL queries in Node.js REST APIs don’t happen because of missing database indexes.</p> <p>They happen because of silent N+1 query patterns executing inside map

<p><em>B-tree internals, column order and planner statistics in Postgres 19, checked against MongoDB's ESR rule.</em></p> <p>Most "add an index" advice stops at <code>CREATE

<p><em>Same uncle, same nephew. Part 1 was about designing and guarding data. Part 2 is about the small, easy-to-miss mistakes that quietly destroy a database over time —