The Guardian transitioned from GitHub-hosted runners to self-hosted runners for their CI/CD pipeline, driven by high costs and performance issues. Running on macOS was particularly expensive due to a tenfold pricing multiplier compared to Linux. Build times were unpredictable, often leading to frustrating timeouts and increased costs. They experimented with various strategies to cut expenses, but none made a significant impact. After a frustrating experience with Xcode Cloud, they decided to leverage an unused Mac Mini to explore the self-hosted option. Setting up the self-hosted runner involved following GitHub’s guidelines, which included installing the necessary software and configuring workflows. The transition required careful management of the environment, particularly around Xcode builds and maintaining cleanliness in job runs. The results were significant: builds became up to 60% faster, and the average run time across all workflows improved by over 120%. Monthly costs dropped by around £400, and developers gained greater control over OS updates and debugging processes. However, there were challenges with queue management due to limited concurrent runners and maintenance responsibilities increased significantly. The team had to deal with physical hardware issues, including ensuring a stable power supply and managing disk space. They learned that a more powerful single machine was easier to manage than multiple smaller ones and emphasized the importance of having a cleanup strategy for artifacts and disk space. Overall, the switch to self-hosted runners, while not without its challenges, provided substantial benefits in speed, cost, and control.