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Go into your next system design interview, or your next design review, knowing why, not just what. Each lesson is an animated video, a written deep dive with code that runs, and a quick quiz, starting with AI Engineering and System Design.
AI EngineeringBeginner 6:28 video
§ 01
Each domain is split into modules, from fundamentals to the internals senior engineers know. Pick one and go deep.
Build real applications with LLMs, agents and tools.
Design systems that are fast, scalable and reliable.
Languages, frameworks and more, taught the same way.
§ 02
Every lesson gives you three ways into the same idea, because understanding sticks when you see it, read it and use it.
01 · Watch
A short animated explainer, narrated, with Vora as your guide: diagrams move, data flows, code runs.
02 · Read
What are LLM evals?
LLM evals are systematic, repeatable tests that judge an LLM, or a system built on one such as an agent, against clear criteria. They're how you know an AI app works, instead of hoping it does.
A written deep dive at your own pace, with code that has been run before it was published.
03 · Practice
A teammate tries a new prompt on the same five questions they always use and says it's better. What's the main problem?
A short quiz that explains every answer, right or wrong.
See the whole lesson: LLM Evals: Why "It Looks Good" Isn't Enough
§ 03
New lessons are added as they pass review.
6:28AI Engineering Beginner 4 min read
LLM evals are systematic, repeatable tests that judge an LLM app against clear criteria. Learn why spot checks fail, how evals differ from classic tests, and the workflow to run them.
Oct 19, 2026
§ 04
Engineers preparing for AI Engineering and System Design interviews, and engineers building real systems who want to know why things work, not just what to type. Both get the same thing: one topic, understood properly.
Yes. Every lesson, video and quiz is free. No paywalls, no pop-ups.
No, there's no sign-up. When you mark a lesson as done, that's saved in your browser only, so it stays on this device and nothing is sent to us.
An animated, narrated video with captions, a written deep dive with callouts and key takeaways, code that is run in a sandbox before it's published, and a short quiz.
Each lesson starts from the author's own notes. Every claim is checked, every code example is run in a sandbox, and the author reviews and signs off on each lesson before it goes live.
There's no fixed schedule: new lessons are added as they pass review. The RSS feed, linked in the footer, announces each one.
Email support@codestoa.com if something isn't working, like a video that won't play or a broken link. Email feedback@codestoa.com to report a mistake in a lesson or suggest a topic. The author reads every message.