[anchochilis]

I find it best to start small with this kind of thing.

Have a single team start practicing GitOps, with an eye to eventually accepting contributions from other dev teams. Establish good patterns in IaC repos, write documentation, add linters and other static checks over time. Tools like Atlantis and ArgoCD can provide deployment automation as well as rollbacks, with opportunities for manually diffing and reviewing changes before applying them.

Edited to add: if your "GitOps" implementation involves anything more complicated than the standard "short-lived PR to mainline" pattern, you are doing it wrong. Avoid environment branches at all costs and follow continuous delivery -- deploy incremental changes frequently.

[raffraffraff]

Upvoted for the edit