Discovered Ruby on Jets in this thread and started watching the video on the project page.

The author addressed the cold start problem here(timestamped) https://youtu.be/a0VKbrgzKso?t=439

Hope it helps :)

I've been meaning to put together a blog entry on our whole stack and will post it on HN probably in the next few months!

nice! All the best to Arist and the team!

There is an auto-warming option -- we keep it warmed up every 5 seconds so it's always super peppy -- requests served within 100ms generally, sometimes much faster. Appdex hovers around 0.996 but some webhooks are included in there so it's probably faster in reality.

DB-wise we utilize the usual postgresql cluster setup with read clones in several regions. We could easily partition by course or by org if we had to but honestly we could probably scale up to series C+ before needing to do that.

Out of interest, have you considered moving to a "serverless" db like Aurora Postgres or even DynamoDb, to avoid the cost of unused database capacity at idle times?

I'd love to, but when I've tried to set up Aurora, it seems impossible to do multi-regional with postgresql (not multi-zonal, but multi-regional). Would love to hear how to do this if anyone has got it working. Last time I tried was about 2 years ago.

Ah ok, interesting - I haven't tried Aurora, my company uses a mixture of RDS postgres and Dynamo. Cockroachdb and Yugabyte also seem like good options but a harder sell for us not being AWS native.

More generally though, all of these "newsql" offerings feel a little too good to be true for me, I can't see how you could really have all the relational integrity of postgres with the elastic scalability of a distributed DB without trading something off. Am I too cynical?