A comprehensive course for backend engineers who are done guessing why their queries are slow. You'll learn to read execution plans like a book, design indexes that actually get used, rewrite queries that cut response times by 10-100x, and build monitoring systems that catch regressions before production does. Every module is taught through real-world Go backend scenarios — no toy examples, no academic fluff. By the end, you'll have the skillset to walk into any codebase, diagnose the database bottleneck in minutes, and ship a fix that holds under load.