Buildkite lets you run CI agents on your servers, theirs, or both, supporting anywhere from 1,000 to 100,000+ concurrent runners. It offers deep parallelization, flaky-test detection with auto-quarantine, test splitting, artifact caching, supply-chain security, and universal pipeline triggers. You can start a 30-day trial with no credit card required.

Since 2013, Buildkite has managed CI pipelines for firms like OpenAI, Airbnb, and Shopify and now orchestrates workflows for companies including NVIDIA, Meta, and Discord. It offers deep parallelization and fan-out orchestration for large-scale workloads, powering software used by over a billion people daily. A 30-day free trial is available.