[tacostakohashi]

It's an interesting area. I worked in that part of a company for a few years, and work with that area as a consumer.

Part of it is using Jenkins/GitLab/GitHub effectively, etc... but... there are also some real shortcomings to setting up elaborate, complicated systems with those tools.

As a first step, devs should have a sane, efficient incremental build setup for their project using CMake/maven/gradle/whatever that works well on their laptop (i.e., forget about all the centralized web-based apps). If they can't do that, no amount of Jenkins/GitLab/GitHub/ADO can help. If their build is slow on its own... then fix it! Running a bad/slow build on a centralized platform just makes things slow for everyone, and then there's no incentive for anyone to fix their own thing because everyone will stil be the victim of everyone else.

Only once that is sorted out, should things be hosted on Jenkins/GitLab/GitHub/ADO... and even then, using a bare minimum, simple, boilerplate setup, not some elaborate configuration that means that the software can not be built without Jenkins/GitLab/GitHub/ADO any more, and nothing can ever be migrated.