(CEO of neon.tech here)

Scaling to zero is tricky. In order to make it work you need to

1. Separate storage and compute which aurora has done

2. Have a proxy between the user and an actual VM in which you host Postgres

3. Spin up this VM after authenticating a connection, stand up Postgres inside the VM and run the query

You need to do all that very quickly- ideally in a couple hundred ms. This can only be accomplished with having a warm pool of VM or having extremely fast microVMs like firecracker.

I believe AWS aurora just uses ec2 and that’s why scale to 0 is turned off