System Design Fundamentals

Answer the recall questions BEFORE revealing. Trying to remember — even failing — builds memory 3x stronger than rereading.

Completed lessons return for review after 1, 3, 7, 21 and 60 days. Review exactly when you're about to forget.

Each module is one small digestible chunk with a one-line memory hook. Finish a chunk fully before starting the next.

Every module ends with a teach-it-back prompt. If you can't explain it simply, you haven't learned it yet.

Mixed revision phases deliberately shuffle topics — discrimination between problem types is what exams test.

Interactive simulators pair visuals with text. Two memory channels beat one — always do the interactives, not just the videos.