Step 1 of 14 · Intro

Design a delivery dispatch system

Pick the right rider for every order, as riders and orders move.

How it works

• ›Riders stream their location, the system keeps an index of where everyone is.
• ›A new order triggers matching: find nearby free riders, offer the order, and record whoever accepts.

What you'll build

1. The API and the data behind it
2. A system for 400 requests a second, then a cheap design for 5,000 location pings
3. A durable queue and workers that absorb the dinner rush
4. A realtime tier, replicas and a limiter for 40,000+
5. A design that survives losing a gateway, a cold cache and the primary database
6. The matching decisions: batching, atomic claims and geo-indexing