The 7 Postgres Indexes That Took My API From 400ms to 40ms

I took one of my APIs from 400ms p95 to 40ms p95 by fixing 7 missing or wrong Postgres indexes. Most of my slow queries were not slow because of bad SQL, they were slow because Postgres had to scan the whole table. Partial indexes and covering indexes did more for me than plain B-tree indexes on primary columns. EXPLAIN ANALYZE and pg_stat_statements are the only two tools you need to find the real bottlenecks. The API in question powers my analytics dashboard. Nothing fancy. A few endpoints tha