I really love the ideas/architecture behind Concourse, but there's a few things that disqualified it in favour of Jenkins for a new CI pipeline during prototyping:

- no hooks to manage worker scaling (https://github.com/concourse/concourse/issues/993). Our builds are _heavy_ and we'd run up an enormous AWS bill without something like (https://wiki.jenkins.io/display/JENKINS/Amazon+EC2+Plugin)

- no way to restart a build, resorting to 'empty commits', which is a huge red flag for useability (https://github.com/concourse/concourse/issues/413)

- limited documentation/examples (network effect)