FWIW, I always found GitLab's CI to be mostly a Travis clone with a few improvements. CircleCI started in a similar place but seemed to improve faster for a few

FWIW, I always found GitLab's CI to be mostly a Travis clone with a few improvements. CircleCI started in a similar place but seemed to improve faster for a few years. Eventually I moved everything to GitHub Actions which always felt mature beyond its age and I've never looked back. Roughly my issues with GitLab CI was that it didn't provide sufficient primitives for a) breaking up the build into a granular build graph, b) correctly passing artifacts between build graph stages (caching wasn't a good solution), and c) guaranteeing at-most-one task in a critical section (such as a deployment). It has been a few years since I last checked on these, but it also sounds like the product hasn't move much recently.