I have a streaming multimedia app that I want to launch. It ingests from the client, does some transformations, then sends it back to them (or to other parties) in realtime. It's pretty novel though - Snapchat adjacent. I can't do it clientside. Nature of the problem. I'm writing it in Rust, so it's relatively fast. But throwing thousands of people at it will still require extreme scale. I'm going to use K8S horizont…
Do some maths.
Get one (1) small EC2 instance on the free tier. Deploy the test version there. Keep adding test clients until the thing is maxed out (presumably on CPU for your application?). That gives you a ceiling for "peak usage". You may find this is surprisingly high.
Come up with a ballpark figure for how many client requests a normal user will make in a day.
You can now start producing cost numbers for using various solutions, from AWS to dedicated hosting. If you don't have deep pockets, do not choose an option which can incur unlimited bills.
Before you can even think of selling it to someone, you need to have a compelling revenue story. Not actual revenue, but a convincing path to revenue. These days that's usually advertising. Can you bung some ads in there from Google to cover startup costs?
Which would you rather have, the system page you in the middle of the night to add more instances manually, or the system do it on your behalf without regard to cost?