Blacksmith was founded by ex-CockroachDB and Faire engineers who experienced firsthand how CI costs can reach millions at scale while still delivering slow builds. The core insight is that GitHub Actions runners use decade-old server CPUs optimized for throughput, not the single-core performance that compilation, testing, and Node.js actually need. Blacksmith replaces these with modern gaming-grade CPUs offering 50%+ higher single-core performance, co-located with warm cache artifacts and persistent NVMe storage for Docker layers. Builds complete in roughly half the time, and at half GitHub's per-minute rate, customers see up to 75% total cost reduction.
The platform adds CI observability that GitHub lacks. Engineers spot misconfigurations and performance regressions through pipeline analytics, run global searches across CI logs, and see failed test logs posted as GitHub comments. Docker layer caching persists across runs so unchanged layers are reused rather than rebuilt, cutting Docker build times from minutes to seconds. Container caching pre-hydrates service containers on runners, removing repeated image pulls from job startup. All runs in Firecracker microVMs providing strong isolation, with SOC 2 Type II certification for enterprise security.
Blacksmith has raised $17.6M including a $10M Series A led by Google Ventures, and is part of Y Combinator W24. The platform serves over 1,000 organizations running 20M+ jobs per month, with customers including Supabase, Ashby, VEED, Chroma, and Clerk. Pricing starts at $0.004 per minute for 2 vCPU x64 runners with 3,000 free minutes monthly. Enterprise plans add 99.9% SLA, white-glove onboarding, and 24/7 support. The team supports open-source projects including Celery, Ladybird, Zen, and Limbo with free CI resources.