fly

Shameless plug: we have an open source tool you can build stuff like this on. It'll run any logic you can implement in JavaScript, we have people doing things like "send traffic to backend with lowest latency" already, it'd be pretty easy to pull in some API data to pick based on cost. https://github.com/superfly/fly

Sure! You can even pick apart the code if you want: https://github.com/superfly/fly 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 re