Figma built FigCache, an in-house stateless RESP-wire-protocol proxy service to replace their fragmented Redis client ecosystem. Driven by connection scalability limits, thundering herd incidents, and inconsistent observability, the team designed a decoupled proxy architecture with first-party client libraries in Go, Ruby, and TypeScript. FigCache centralizes traffic routing, multiplexes connections to reduce pressure on Redis clusters, and uses a Starlark-based configuration system to compose dynamic engine trees for routing, filtering, and command manipulation. The migration was executed gradually with feature flags and reversibility guarantees. Since rollout, Figma's caching layer has achieved six nines of uptime, zero-downtime failovers, and dramatically reduced incident diagnosis time.
Table of contents
Growing pains in cachingDesigning for longevityAn opportunity for new foundational technologiesWhy we built instead of boughtFigCache, our in-house caching service and client ecosystemThe big migrationWhat we unlockedSort: