BazelCon 2024

Container images are a ubiquitous mechanism for deploying applications in the modern computing landscape. Everything from services deployed on bare-metal Kubernetes to AWS Lambda functions depend on container images. Building these images quickly and efficiently is critical to keeping CI/CD responsive. In recent years, Stripe has undergone dual migrations. One, to a service oriented architecture. Two, to running services inside Kubernetes. Together, these migrations meant our CI pipelines to build containers became slower and more expensive with each passing month. With a build producing over a terabyte of images, Bazel just couldn't build them fast enough! Even disk space was in short supply. Learn how we flipped the script on our container builds by leveraging BwoB (Build without the Bytes). Now, we can build 1300+ container images in just a couple minutes with plenty of headroom for more. Bazel's entire output space fits in RAM and there's never a single byte of container images on disk!