5-Day Free Course · Computer Science

Database Internals: What Happens Under the Hood

Most developers treat databases as black boxes. This course opens them up. B-trees, write-ahead logging, MVCC, query planning, and storage engines — explained with diagrams, code, and references to the PostgreSQL and SQLite source.

5 days self-paced
Free forever
Text + external video refs
No signup required
$python main.py Loading course materials... $pytest -x --tb=short PASSED 5 days $git commit -m "day 5 done" [main] 1 file changed $
5
Days
30+
Code Examples
4+
External Videos
$0
Forever Free

No videos. On purpose.

This is a text-first course that links out to the best supporting material on the internet instead of trying to replace it. The goal is to make this the best course on database internals and systems engineering you can find — even without producing a single minute of custom video.

Practitioner-tested, not vendor marketing

This course is built by people who ship production database systems for a living. It reflects how things actually work on real projects — not how the documentation describes them.

Code you can run, not demos you can watch

Every day has working code snippets you can paste into your editor and run right now. The emphasis is on understanding what each line does, not memorizing syntax.

Links to the canonical sources

Instead of shooting videos that go stale in six months, Precision AI Academy links to the definitive open-source implementations, official documentation, and the best conference talks on the topic.

Completes in 5 one-hour sessions

Each day is designed to finish in about an hour of focused reading plus hands-on work. You can do the whole course over a week of lunch breaks. No calendar commitment, no live classes, no quizzes.

The 5 Days

Each day stands alone. Read them in order for the full picture, or jump straight to the day that answers the question you have today.

The best external videos on this topic.

Instead of shooting our own videos, Precision AI Academy links to the best deep-dives already on YouTube. Watch them alongside the course. All external, all free, all from builders who ship this stuff.

Read the source. Every line.

The best way to understand any technology is to read the production-grade implementations that prove it works. These repositories implement patterns from every day of this course.

Three kinds of people read this.

Backend Engineers Debugging Slow Queries

You write SQL but slow queries feel like magic. This course teaches you to read execution plans and understand exactly why a query is slow.

Data Engineers Scaling Pipelines

Your warehouse queries are slow and VACUUM keeps running. Understanding internals tells you which knobs to turn.

Engineers Evaluating Databases

You need to pick between Postgres, SQLite, MongoDB, and RocksDB. This course explains the storage engine tradeoffs, not the marketing.

Want to Go Deeper in Person?

The 2-day in-person Precision AI Academy bootcamp covers database internals and systems engineering hands-on. 5 U.S. cities. $1,490. 40 seats max. June–October 2026 (Thu–Fri).

Reserve Your Seat