This is really neat--congrats on the launch. Can you tell us a bit about the infrastructure behind it? Is there any spin-up time, like AWS Lambda has? Presumably "fly.cache" persists between requests, but is other memory shared between requests?
There's no warmup time. We spent some time with various OSS FaaS tools and that was pretty killer. When you deploy, we build a v8 snapshot of your code, then push it out to all the Edge Servers. It's already in memory and ready to rock when a request comes in — less than 1ms to get to your code for most apps.
fly.cache does persist, although it will vary per region (that's a surprising thing we learned about CDNs, cache contents vary per region quite a lot). It's volatile so you shouldn't rely on it for durable data storage, but you also pay for what you use so we have a strong incentive to not evict cache data any more than you request. :)
The global context _can_ be shared between requests but you can't really count on it. There's no guaranty that one request will run in the same context (or isolate or server) as a previous one.
We have some ideas for more durable and structured storage down the road. Building APIs that are location agnostic is fun, but a little mind bending.
Right now it's _best_ suited for building proxy-like applications. Aggregating APIs, speeding up existing apps without touching them, user aware caching, etc.
But we're getting constant pressure to expand the scope of what they do, too, which is pretty exciting.
Hmmm...