System Design Arcade

The AI Arcade Eight new games on the interview round that didn't exist three years ago: RAG systems, LLM serving, feed ranking, embeddings, feature stores, ML observability, AI guardrails, and GPU infrastructure. Two More Games Vector Vault joins the Tool Arcade, and Design a Key-Value Store joins the Problem Arcade. Review That Actually Spaces Out Clearing a missed challenge no longer retires it. It comes back on a widening schedule of a day, three days, a week, three weeks, then two months, because recalling something once is what schedules the next recall. Straight Into the Game First launch drops you straight into a playable level, and the app draws instantly instead of waiting on the network. Sign in free when you are ready to unlock every level and sync. Fairer Scoring On multi-select questions, wrong picks now cancel correct ones, and selecting everything scores zero instead of half credit. Sharper Questions A full correctness pass over every game, plus rewrites of hundreds of answer options so the right one is no longer guessable from its length or punctuation. Progress You Keep Levels save the moment you finish them, signing in no longer loses local progress, and your badges survive the catalog growing.