30+ Updates per Second per Account: Uber Scales Ledger Processing with Batching
Uber's new ledger processing system uses 250ms batching and Redis coordination to handle over 30 updates per second per account under high contention, replacing per-request processing with batched atomic updates. The double-entry accounting model ensures consistency, and the three-stage workflow (grouping, atomic execution, persistence) cuts processing from hours to minutes while maintaining auditability.