Fly.io doesn't set a maximum of 8 hours of alive time on your instance.
Also, MicroVMs can't be exposed directly to the web. Your code running in them can only be executed via API calls with attached auth tokens - so if you wanted to host a public facing API or website with them you'd need to implement your own additional layer in front.
Something I appreciate about Fly (disclaimer: they support my work) is that the pricing is fixed - you pay $1.94/month (less if you suspend your machine) for the smallest instance, up to $976.25/month for the largest (16 CPUs, 128GB) plus predictable costs for volume storage.
The only variable outside your control is bandwidth, and that's unlikely to cause a nasty shock.
Contrast with any of the more "elastic" hosting providers - Vercel, Cloud Run - and you're much less likely to get a horrifying bill if something gets overly-crawled or goes viral.
I'm pretty proud of this:
https://fly.io/blog/accident-forgiveness/
A way we simply suck at business: we didn't keep beating the drum about this after we wrote the policy up. We just sort of figured everyone read the blog post and moved on. We probably should have been continuously making noise about it.
What you get from having a company made almost entirely of engineers.
Fly.io's Sprites [1] do offer public web access as an option. They also have dynamic pricing.
https://sprites.dev
To a first approximation everything in this space has dynamic pricing. If it's not priced dynamically, you're presumably paying a premium either on a commit or in gym pricing.
I don't know what the right term is, but maybe "deterministic" pricing (this is not the right term, but maybe closer). That is, I'm not going to know how much a sprite cost until I see the bill (or look up the live usage report), whereas if I spin up a Fly Machine, I know exactly how much I'm going to pay per unit of time.
(Both make sense for their respective use cases.)
Ah, that makes sense. Yeah, that's a technical limitation! I'm sure we'll work through it at some point this year, but it's a consequence of the fact that for most people, most of their Sprites are dormant most of the time; it's how you comfortably get to having 20-30 Sprites (making a new one any time you do something new) for every user.
It's a good callout, a genuine difference between Sprites and Fly Machines. Believe it or not, it's intended to make Sprites cheaper than Machines.
I absolutely believe it! And feel the pricing model makes perfect sense for the use case.