Module 19 19 lessons 190 min
Classic algorithms in action
Interviewers say “use consistent hashing” or “add a Bloom filter” as if everyone has watched one work. Here you do: each one runs in front of you, and you break it on purpose.
In this module
19 Simulate
- 19.1Consistent hashingAdd a server to the ring and watch which keys move - then add virtual nodes.Simulate10 min
- 19.2Bloom filter“Definitely not” or “maybe”: tune its size and count the false positives.Simulate10 min
- 19.3HyperLogLogCount millions of unique visitors in 12 KB of memory.Simulate10 min
- 19.4Count-min sketch and top-KFind tonight's trending dishes without counting every one exactly.Simulate10 min
- 19.5Geohash and quadtreeFind the nearest rider without checking every rider in the city.Simulate10 min
- 19.6TrieAutocomplete: suggestions after every letter typed.Simulate10 min
- 19.7Inverted indexHow search finds every menu with “paneer” in it.Simulate10 min
- 19.8B-tree vs LSM treeTwo ways to store data on disk: fast reads or fast writes.Simulate10 min
- 19.9Write-ahead logCrash the database mid-write, then watch it recover.Simulate10 min
- 19.10Merkle treeFind what differs between two replicas without comparing everything.Simulate10 min
- 19.11Snowflake IDsUnique, sortable IDs from many machines - until a clock jumps back.Simulate10 min
- 19.12Lamport and vector clocksPut events in order when no clock can be trusted.Simulate10 min
- 19.13Gossip and failure detectionHow a cluster spreads news and notices a dead machine.Simulate10 min
- 19.14Quorum reads and writesChange N, R and W, kill a node, and see what readers get.Simulate10 min
- 19.15RaftElect a leader, replicate a log, then cut the network.Simulate10 min
- 19.16Leases and fencing tokensA paused lock holder wakes up and tries to write.Simulate10 min
- 19.17CRDTsTwo offline phones edit the same cart. Merge them without losing anything.Simulate10 min
- 19.18Fan-out on write vs readPost as a celebrity with 10 million followers, and watch the feed build.Simulate10 min
- 19.19Sharded countersCount a million likes a second without one hot row.Simulate10 min