How We Designed Our Continuous Integration System to Be More Than 50% Faster

Pinterest's Engineering Productivity team slashed CI build times by over 50% in one week. Here's the architecture that made it possible.

Pinterest's team rebuilt their Continuous Integration system for Optimus, a monorepo with 120+ Java services serving 300 monthly contributors. They moved from running all targets to intelligently selecting only what changed, using Bazel queries and custom tooling.

Key Takeaways

• P50 build times dropped from 52 to 19 minutes (2.7x faster)
• Custom build-collector CLI uses Bazel queries to find minimal target sets
• Custom release rules abstract infrastructure and enable parallel artifact generation
• Language-based monorepos reduce pipeline management overhead
• Dispatcher model parallelizes test and release targets across workers

The team's custom Bazel release rules create an abstraction that most developers don't even see, but it powers their entire deployment workflow.