GitHub Actions vs. Jenkins vs. CircleCI: How FreeAgent Cut Its Test Infrastructure Spend by 90%

FreeAgent, the accounting software company, moved its CI/CD workflows off Jenkins and onto GitHub Actions, and reported a 90% reduction in its monthly infrastructure spend for running tests. Nylas made the same Jenkins-to-Actions move and cut its deployment time by 30%, then started seeing whole weeks with zero build failures. Neither team changed what they were building. They changed the machine that builds it, and the difference showed up on the invoice and in the engineers' week.

Then there's the other side of choosing a CI platform, the one nobody puts in a benchmark. In January 2023, CircleCI told every customer to rotate every secret stored on the platform, after attackers got access to customer secrets. Open-source project conda-forge, which had stopped using CircleCI but never removed its tokens, ended up with an outage of about five days while it rotated credentials across all its CI services.…