Makefiles are machine-readable documentation that make your workflow reproducible. If the build process is a very continuous flow of operations within scope, it will do it well and also act as a documentation of all the dependence. For some long-term projects, Make has been used extensively and being maintained to do the job.
GoCD is easy to set up. So if you just want to get some pipelines up & running quickly, & they're quite stable, or you can have many pipelines for different needs then GoCD is great. Still, if you only want to have a few pipelines, but with the flexibility to run them with different parameters dynamically, then Jenkins is better.
Pipeline-as-Code works really well. All our pipelines are defined in yml files, which are checked into SCM.
The ability to link multiple pipelines together is really cool. Later pipelines can declare a dependency to pick up the build artifacts of earlier ones.
Agents definition is really great. We can define multiple different kinds of environments to best suit our diverse build systems.
In general, it is fair to say the support is sufficient although we do not deal with support directly. There are a lot of forum people chiming in with suggestions or recommendations of particular usage or issues we run into. Since it is open software, patch and fixes will be available from time to time. A lot of information is available in the web now for knowing GNU Make from learning, example, teaching, etc.
I'm a full-stack developer that has used various build tools, including Maven, Gradle, and NPM/yarn. For our C projects, I also investigated CMake and Ninja, but they seemed more difficult to learn and more tedious to work with. GNU Make is a single binary that can be easily downloaded, even for Windows under MingW32, is straightforward to learn, and works pretty well despite its age.
I prefer using GoCD compared to Jenkins. The UI makes sense, I like the simplicity to hit the 'Play' button for a straightforward deployment of the 'Play +' if you need to override some settings when deploying whereas Jenkins, you have the whole page for each pipeline. The environment makes sense but can often confuse the user while GoCD simply has a drop-down to select your environment.
Settings.xml need to be backed up periodically. It contains all the settings for your pipelines! We accidentally deleted before and we have to restore and re-create several missing pipelines
More straight forward use of API and allows filtering e.g., pull all pipelines triggered after this date
