[p_l]

Stack Overflow is also a) old system built before a lot of current management tech was available openly b) Very single-application centered.

EDIT: To expand on it - they had to manually build a lot of what could be much easier handled today, and thus had no incentive to change later. Interestingly enough, SO has a lot of moving parts distributed over multiple servers, even if all of those servers used to fit into 1-3 racks per DC.

[andrewingram]

The single vs multiple application centric thing is a point that's not made enough. Google is basically now a company all about spinning up new products, rather than just periodically adding a new piece of tech to an existing product. As a layperson, Kubernetes _appears_ to be about making it easier to spin up (and run) new products, so it feels more appropriate for Google-like org types.

[p_l]

There are also a lot many more applications one might need to run, especially when scaling beyond one-two people running all development on their laptops/desktops and not having a company yet - especially when one doesn't have valley-style funding.

Also these days you might not want to implement login functionality from scratch, or have better logging, monitoring, etc. and that might involve running more applications than just your LAMP stack.