System Design Specs

Interactive architecture diagrams for a handful of distributed systems.

Distributed Transactional Database

Spanner/CockroachDB-class: Raft-replicated range-partitioned store, one architecture across read-heavy, write-heavy, and flash-sale workloads.

Distributed Denylist

Globally-replicated blocklist with zero remote hops on the request path — "is it available?" becomes "how stale is the local copy?"

Distributed Doubly Linked List

Billions of nodes with O(1) splice-insert, order encoded as a fractional sort key so inserts touch exactly one row.

GitHub Actions

CI/CD platform: matching millions of concurrent jobs to an ephemeral runner fleet while ingesting ~1 GB/s of live logs.

Live Poll

Real-time poll broadcasting per-option voter identities to 1M concurrent viewers within a few hundred ms of each vote.

Mobile Push Notification Service

Server-side fanout to APNs/FCM: token registry, dedup, rate-limiting, per-platform delivery, and feedback cleanup.