If you are a maker or founder then where do you host your saas?

aws

I used Linode and Heroku. But started to build with Next.js lately so I'd probably go with Vercel.

The railway.app is quite a good alternative. It is comparatively way cheaper, but an excellent solution. From the options you provided, AWS is good.

For me, it depends on the tech stack. PodCards (https://getpodcards.com) is a SvelteKit app and so I host that on Netlify - totally free. Unsummary (https://unsummary.com) is a Laravel Jetstream app so I host that on Laravel Forge.