Let’s say I have to host 25 websites… How do I know how powerful should my VPS be? Which specs it should have, how fast the connection should be to handle X visits per day?
How do you understand which are your system requirements BEFORE deploying a project? Do you just make estimates and then scale up? Or there’s some kind of tool to benchmark? how to handle this kind of stuff?
Don’t worry about scaling UP. Worry about scaling OUT. Make your service small, you don’t have to go micro but keep it as light as possible. Then when you need to, you can always add another clone of it. And another, and another.