It sometimes blows my mind how reductionist and simplistic a world-view it's possible to have and yet still attain some degree of success.

Shovels and mechanical excavators both exist and have a place on a building site. If you talk to a workman he may well tell you he has regular hammer with him at all times but will use a sledgehammer and even rent a pile driver on occasion if the task demands it.

And yet somehow we as software engineers are supposed to restrict ourselves to The One True Tool[tm] (which varies based on time and fashion) and use it for everything. It's such an obviously dumb approach that even people who do basic manual labour realise its shortcomings. Sometimes they will use a forklift truck to move things, sometimes an HGV, sometimes they will put things in a wheelbarrow and sometimes they will carry them by hand. But us? No. Sophisticated engineers as we are there is One Way and it doesn't matter if you're a 3 person startup or you're Google, if you deploy once per year to a single big server or multiple times per day to a farm of thousands of hosts you're supposed to do it that one way no matter what.

The real rule is this: Use your judgement.

You're supposed to be smart. You're supposed to be good. Be good. Figure out what's actually going on and how best to solve the problems in your situation. Don't rely on everyone else to tell you what to do or blindly apply "best practises" invented by someone who doesn't know a thing about what you're trying to do. Yes consider the experiences of others and learn from their mistakes where possible, but use your own goddamn brain and skill. That's why they pay you the big bucks.