From a StackShare Community member: "Currently we use Travis CI and have optimized it as much as we can so our builds are fairly quick. Our boss is all about redundancy so we are looking for another solution to fall back on in case Travis goes down and/or jacks prices way up (they were recently acquired). Could someone recommend which CI we should go with and if they have time, an explanation of how they're different?"
If you are considering Jenkins I would recommend at least checking out Buildkite. The agents are self-hosted (like Jenkins) but the interface is hosted for you. It meshes up some of the things I like about hosted services (pipeline definitions in YAML, managed interface and authentication) with things I like about Jenkins (local customizable agent images, secrets only on own instances, custom agent level scripts, sizing instances to your needs).
We use CircleCI because of the better value it provides in its plans. I'm sure we could have used Travis just as easily but we found CircleCI's pricing to be more reasonable. In the two years since we signed up, the service has improved. CircleCI is always innovating and iterating on their platform. We have been very satisfied.
I prefer CircleCI over Jenkins for the following reasons:
1. each repo has an isolated build container - no web of dependencies to manage
2. no ocean of plugins to configure - all what you need is the yaml file and, maybe, in a custom build image
3. decentralized execution of builds - no master/agents complexity