The most important thing for any app is a consistent build/deployment process. I've been doing DevOps and CI/CD for many years now and having manual build/release steps is a huge source for errors and issues. Every single time I kick off a build and release, I'm happy and smiling because everything is running smooth and you don't have to worry about messing things up. But getting their is a real challenge!
Here are the slides of my DevOps Patterns and Anti-Patterns talk at Experts Live 2017. Experts Live Europe - DevOps Patterns and Antipatterns