Blacksmith operates a managed cloud platform for continuous integration, sold primarily as a drop-in replacement for GitHub Actions runners. Customers change the runs-on tag in an existing workflow and the same jobs execute on Blacksmith's bare-metal hardware instead of GitHub's, which the company markets as roughly twice as fast at 50-75% lower cost. The stack is purpose-built for CI: high single-core-performance gaming CPUs, co-located cache artifacts, persistent Docker layer caching on NVMe, and instant microVM provisioning. Blacksmith says more than 3,000 organizations, including Vercel, Supabase, Clerk, Mercury, and Ashby, run tens of millions of jobs on it each month.