Design Lab

Some things about distributed systems are opaque in prose and obvious in one animation. These are 5 small simulators for exactly those: you pick a strategy, break something, and watch what happens. Included with any Prepd pass.

• Back of Envelope — Estimate the numbers before you draw the boxes. Teaches Capacity estimation; closes out “Roughly what scale are we at?” (5 min).
• The Reshard — Kill a node. Watch how much of your cache goes cold. Teaches Consistent hashing; closes out “Why consistent hashing rather than modulo?” (4 min).
• Rate Limiter Lab — A burst arrives. Which algorithm holds? Teaches Throttling algorithms; closes out “Design a rate limiter.” (5 min).
• Cache Showdown — LRU is the answer everyone gives. Watch it lose. Teaches Eviction tradeoffs; closes out “What’s your eviction policy, and why?” (5 min).
• Hot Shard — Pick a shard key. Then a celebrity signs up. Teaches Partition skew; closes out “How would you shard this?” (4 min).