Study Cards: System Design

One deck for all 16 classes, from C1 (what system design is) to C16 (the case studies), subpages included: 460 cards, each a section of a class, with that class's own numbers and the BoxOffice example. There are two modes.

• Study. Read the question, answer it in your head and flip the card. Then say how it went: missed, almost or got it. Cards you missed come back first; the ones you got right wait until the end. Your progress is saved in this browser.
• Challenge. A ten-round game: each round shows a situation from production or from a design interview ("the payment provider is slow and every checkout thread is waiting…") and three concept cards. Pick the card that explains or solves the situation. Right answers in a row multiply your points; each miss costs a life and sends the card to the missed box of the Study mode. There are 272 situations.

The filters build the deck. Pick one or more topics (F foundations, D distributed systems, E edge & compute, S storage, M messaging, O operations, A AI, P performance & cases) and, within them, any classes or class pages you like: study only this week's class or, when reviewing for an exam, only one stage of a design. Each card's colour is its design stage, the same as in the concept map: blue for requirements & numbers, purple for building blocks, teal for data & consistency, orange for operating at scale; the stage's name is also written on the card's band. The dots at the bottom give the level: warm-up, practice or challenge. On the keyboard, space flips the card and 1, 2 and 3 give your grade (or pick a card, in the Challenge).

Every card links to the section of the class where the concept is taught. To see how the concepts connect, use the concept map; to look up formulas and numbers, the cheat sheet; to practise with exercises, the workbook; to rehearse a full design out loud, the interview preparation.