In the job itself is fine... unless you want to version control it. This is a historical Jenkins weak-point. The plugins that exist to try to solve the problem

In the job itself is fine... unless you want to version control it. This is a historical Jenkins weak-point. The plugins that exist to try to solve the problem are clumsy. This Jenkinsfile is their solution to the problem. I'm saying it's not a very well thought-out solution, because now they're forcing us to put this thing that's not part of the project in the project, if we want it version-controlled.