Plain EC2, backend in PHP.
That's slightly horrific. Weirdware NIH deploy system, no containers, PHP.
Running an actual process on an actual server has been around since time immemorial, as has doing the "atomic" deploy thing (which I'm guessing is just updating a symlink from cold to hot).
The approach is refreshingly sane.
You would be surprised at how 99.9% of the companies work. Including a lot of departments inside Google, Amazon and Netflix.
Maybe you were being sarcastic and I felt for it since you stressed it a bit too much.
The complexity of the infra and deployments are always relative to the size of the company, and no two companies are alike there. Small or big, it's all bespoke. Even if a few pieces are shared as open source projects, there's a veritable iceberg of complexity in the form of inhouse knowledge and tooling in each of the companies, there is nothing even close to a standard deployment system in either green field startups or FAANGs today.
I'd argue that the contemporary infatuation with mastery of complex toolchains as being the only possible solution to modern technical problems is far more horrific.
Smart businesses focus on simple, effective solutions and avoid hiring engineers who obsess with rewriting everything using the latest over-hyped technology.