Semaphore

Semaphore is an open source CI/CD platform that enables engineers to test and deploy code efficiently. Founded over a decade ago, the company serves more than 30,000 engineers and over 1,000 customers across 100+ countries. Its clients range from SMBs and fast-growing startups to Fortune 500 companies.

The platform is available as a hosted service or self-hosted, supporting Docker, Kubernetes, iOS, Android, and all major programming languages. It is described as an AI-driven platform, with optimized bare-metal servers delivering build speeds up to twice as fast as alternatives. Reported customer outcomes include CI build time reductions from over an hour to 10-12 minutes, pipeline durations cut in half, and cost savings of up to 38%.

Semaphore operates as a 100% remote team. In 2024, the company open-sourced its core platform under the Apache 2.0 licence, with ongoing development shaped by both the team and its community of users.