Our cloud-exit savings will now top ten million over five years
world.hey.com
world.hey.com
It does require people with different skills to run it, which has to be taken into account.
Perhaps one thing that on-prem is bad at is efficiency: historically, companies often have too much capacity, mostly to cover for peaks of activity, but this leads to lower average server utilisation.
If you're starting a new Rails app and live in the EU, the optimal strategy is pretty clear:
Get a 64-thread box on Hetzner for 250 euro a month, allocate 20% of it to the DB, 40% to web, 40% to bg, then just forget about scaling until you're making money hand over fist.
At a certain point, self-hosting is so much cheaper than PaaS that you can way overprovision your server and not worry about it until you're making serious money.