> Colocated systems tend to work very well at first when the original engineers who set it up are all still at the company and it hasn't run long enough to start encountering rare failure modes. They quickly become a nightmare when your engineering staff turns over multiple times and nobody can remember who knows how to do what on the colocated system or if the documentation is up to date or not.

Everything above really sounds like it's just regurgitating AWS sales person talking points.

Sounds like a systemic management / CTO-level problem to me if a company isn't willing to put in place the hiring practices and compensation, documentation systems and operational procedures to deal with that sort of concern.

If your core engineering staff is turning over multiple times for arbitrary reasons you have other problems to deal with.

> Engineers can't set up, maintain, and do on-call for the colocated setup without subtracting from their primary working hours.

If a company can't hire datacenter techs to install hardware, cables, and swap hardware as smart remote hands, maintaining as little as a couple of 45RU cabinets of gear, you also have other management/systemic problems to deal with. I'm looking at this from the point of view of a facilities based bare metal ISP that owns/runs all of its own hardware, and can tell you it's not rocket science.