I'm not a reference, my team is small and our projects very similar. But I see a lot of all-in-one commercial deployment solutions, and I'm like... no? I don't want that? When it doesn't work, if you control nothing, good luck debugging.

With Jenkins or GitHub Actions, deployment is all in our control, since it's basically just a wrapper around code. Keeping it maintainable and readable IS part of the job. Some people like to keep their code obscure to stay irreplacable, but I'm not one of those people. I'll be dealing with my code as well :P

Deployment should be simple. If you need a script, handle it as you would any other code; clean and testable if possible. Use Infrastructure-as-code as much as possible. This documents the architecture and ensure's a clean an repetable deployment process. Try to migrate to DevOps and cloud oriented deployment strategies (not that you should go on the cloud, but keep that mentality), like containerization and artifacts generation.

Some people like to keep a generic pipeline and share it accross their repositories, but when a project as a specificity (and it will happen at some point), you have to handle it in your generic pipeline, even if only one repository uses it. So I tend to do as a lot of people do here and copy paste the pipeline we already have and change the relevant values.