CircleCI Pipeline Platform

CircleCI is a continuous integration and delivery platform founded by Paul Biggar and Allen Risbridger in 2011, headquartered in San Francisco, providing cloud-based and self-hosted pipeline execution for building, testing, and deploying applications, with a configuration-driven approach using YAML files, native Docker support, parallel execution, and integration with over one hundred services including GitHub, Bitbucket, GitLab, AWS, Google Cloud, Slack, and Jira, adopted by over one hundred thousand organizations including Spotify, Stripe, GoPro, and DoorDash. The pipeline configuration uses a YAML file in the repository root, defining jobs composed of steps that run commands, Docker containers, machine instances, or macOS environments, with workflows coordinating job execution through dependencies, parallelism, manual approval gates, scheduled triggers, and conditional execution based on branch names, tags, or file changes. The resource classes provide different compute sizes including small, medium, large, and xlarge instances, with GPU instances for machine learning workloads, macOS instances for iOS development, and ARM instances, while Docker layer caching and test splitting reduce pipeline times. The orbs provide reusable packages of configuration for common tasks and third-party integrations, with the orb registry hosting over six thousand orbs. The insights dashboard provides pipeline analytics. The self-hosted runners for on-premise execution. Designed for engineering teams building CI/CD pipelines.