I've worked at a smaller project where it worked just fine. The key I think is to have the project be small enough to be able to fit in my head.
That and have an identical test server. I used to make changes locally, test it locally, then make the same change on test, have someone else look at it, get a lgtm, and do the same thing on the production machine. It sounds like a lot of steps but it is pretty straightforward.
Sadly, it probably doesn't work with bigger teams or more complicated projects.
A lot of things work on a small project where everybody knows what they are doing and can keep all the dependencies and data structure in their heads. Logging to the production server and editing PHP file right where apache is looking at it and fixing stuff with sql commands in the production database to address customer complaints.
The big question is what everyone else should be doing that survives the touch with unevenly distributed amounts of technical expertise and amount fucks given about result.
That and have an identical test server. I used to make changes locally, test it locally, then make the same change on test, have someone else look at it, get a lgtm, and do the same thing on the production machine. It sounds like a lot of steps but it is pretty straightforward.
Sadly, it probably doesn't work with bigger teams or more complicated projects.