sharding
3 pages tagged sharding.
System Design
001easy
URL Shortener
Designing a read-heavy URL shortener end to end — Base62 key space sizing, distributed ID generation, the 301-vs-302 decision that cannot be undone, four-tier caching, hot-link handling, and abuse control.
003medium
Pastebin
Designing a text-sharing service end to end — key generation, blob vs metadata storage, expiry and burn-after-read semantics, CDN-backed read path, and the optimizations that keep a read-heavy system cheap.
004hard
Chat System
Designing a real-time messaging system end to end — persistent connections and session routing, per-conversation ordering, at-least-once delivery with client dedupe, offline push, multi-device sync, presence, and where end-to-end encryption changes the architecture.