Ask HN: Inexpensive, cutoff SaaS for HTTP and compute?

Hi HN, I'd like to solicit your wisdom in locating cheap HTTP+compute PaaS hosting options.

My requirements:

- TLS

- Access to raw HTTP payload

- Automatic shutoff of service with free-of-charge 503s if some threshold exceeded (e.g. if it gets hugged to death)

Nice to have:

- User-configurable cutoff threshold

- Billed by request and/or CPU use instead of flat fee

- A good metrics/analytics/billing dashboard

- HTTP/2

- Multiple supported languages, comformance to idiomatic language APIs instead of proprietary platform

Intended usecase:

- HTTP request comes in

- Process request (e.g. dig up page from storage, make API calls to the outside, or run some computation)

- HTTP response goes out

Thanks! I'm aware this sounds a lot like Google AppEngine, but i'm interested in alternatives.