Bazel vs Concourse: What are the differences?
Developers describe Bazel as "Correct, reproducible, fast builds for everyone". Bazel is a build tool that builds code quickly and reliably. It is used to build the majority of Google's software, and thus it has been designed to handle build problems present in Google's development environment. On the other hand, Concourse is detailed as "Pipeline-based CI system written in Go". Concourse's principles reduce the risk of switching to and from Concourse, by encouraging practices that decouple your project from your CI's little details, and keeping all configuration in declarative files that can be checked into version control.
Bazel and Concourse are primarily classified as "Java Build" and "Continuous Integration" tools respectively.
"Fast" is the primary reason why developers consider Bazel over the competitors, whereas "Real pipelines" was stated as the key factor in picking Concourse.
Bazel and Concourse are both open source tools. It seems that Bazel with 12.2K GitHub stars and 2K forks on GitHub has more adoption than Concourse with 3.92K GitHub stars and 472 GitHub forks.
Starbucks, DigitalOcean, and HelloFresh are some of the popular companies that use Concourse, whereas Bazel is used by Square, Asana, and Google. Concourse has a broader approval, being mentioned in 18 company stacks & 17 developers stacks; compared to Bazel, which is listed in 11 company stacks and 7 developer stacks.