How we tripled max concurrent jobs to boost performance of GitHub Actions

GitHub Actions have undergone significant performance enhancements since becoming generally available on GitHub Enterprise Server 3.0, with improvements leading to a threefold increase in concurrent jobs on 96-core machines, from 2,200 on GHES 3.2 to 7,000 on GHES 3.6. Key improvements include enabling caching for workflow secrets and callback URLs, optimizing the orchestration framework by transitioning from a single-column blob storage to incremental reads and writes, and reducing the load from postbacks by evaluating their necessity and switching to a streamlined message queue system. These changes have significantly reduced CPU consumption and improved the execution speed of workflows, demonstrating the importance of revisiting and refining core processes as platforms evolve. The enhancements not only satisfy engineering goals but also have tangible benefits for customers who rely on GitHub Actions for efficient code deployment.