GitLab CI/CD Caching Methods Can Cut Docker Build Times by Up to 80%

Developers often face long CI/CD pipeline runs because GitLab's ephemeral runners start with an empty Docker cache, forcing layers to be rebuilt on every commit. Pulling base images from Docker Hub also frequently hits rate limits, causing 429 errors. GitLab offers two built-in features to address both issues: Container Registry with BuildKit layer caching and the Dependency Proxy, which acts as a local pull-through cache for upstream images. The author's guide shows how combining these techniques, along with a layer-friendly Dockerfile ordering, can reduce container build times by as much as 80 percent.