Interactive architecture diagrams for a handful of distributed systems.
Staggered rollouts + version revert: a stateless hash-bucket decides each device's version, health-gated ramps, and revert in <1 s.
Spanner/CockroachDB-class: Raft-replicated range-partitioned store, one architecture across read-heavy, write-heavy, and flash-sale workloads.
Globally-replicated blocklist with zero remote hops on the request path — "is it available?" becomes "how stale is the local copy?"
Billions of nodes with O(1) splice-insert, order encoded as a fractional sort key so inserts touch exactly one row.
CI/CD platform: matching millions of concurrent jobs to an ephemeral runner fleet while ingesting ~1 GB/s of live logs.
Cron + ad-hoc at 25K executions/s peak: retries with backoff, exactly-once-ish dispatch, and a year of execution history.
Real-time poll broadcasting per-option voter identities to 1M concurrent viewers within a few hundred ms of each vote.
Search, directions and turn-by-turn for 1M concurrent navigators: a precomputed road graph in RAM, live traffic streamed in as 200K GPS probes/s.
Server-side fanout to APNs/FCM: token registry, dedup, rate-limiting, per-platform delivery, and feedback cleanup.
Ticketmaster-class flash sales: 500K users in 60 s for 50K seats, metered through a virtual waiting room so no seat is ever sold twice.
"Top K most-viewed items" over multiple time windows at platform scale — exact counting vs. sketches, weighed as a real tradeoff.