Just joined a new company and can only describe the merge process as madness.....is it or am I the one that is mad?!

They have the following branches:

UAT#_Development branch
UAT#_Branch (this kicks of a build to a machine named UAT#)

Each developer has a branch with the # being a number 1 to 6 except 5 which has been reserved for UAT_Testing branch.

They are working on a massive monolith (73 projects), it has direct references to projects with no nuget packages. To build the solution requires building other solutions in a particular order, in short a total fucking mess.

Developer workflow:

Branch from master with a feature or hotfix branch

Make commits to said branch and test manually as there are no automated tests

Push the commits to their UAT#_Development branch, this branch isn't recreated each time and may have differences to all the other UAT#_Development branches.

Once happy create a pull request to merge from UAT#_Development to UAT#_Branch you can approve your own pull request, this kicks off a build and pushes it to a server that is named UAT#.

Developer reviews changes on the UAT# server.

QA team create a UAT/year/month/day branch. Then tell developers to merge their UAT#_branch branches in to the previously created branch, this has to be done in order and that is done through a flurry of emails.

Once all merges are in it then gets pushed to a UAT_Testing branch which kicks off a build, again not a single automated test, and is manually tested by the QA team. If happy they create a release branch named Release/year/month/day and push the changes into it.

A pull request from the release branch is then made to pre-live environment where upon merge a build is kicked off. If that passes testing then a pull request to live is created and the code goes out into production.

Ahhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh it's a total mess. I knew when I took on this job it would be a challenge but nothing has prepped me for the scale of the challenge!! My last place it was trunk based development, commit straight to master, build kicks off with automated testing and that just gets pushed through each of the environments, so easy, so simple!

They tell me this all came about because they previously used EntityFramework EDMX models for the database and it caused merge hell.

What branching methodology do you use and why? We've been using a trunk based development model, but I'm reviewing others.