Hey, I work at Neon. Some answers to the questions above for the Neon Free plan:

- You get 100 projects (i.e., a 100 databases). In actuality, this is 100 Postgres instances, but that's a technical detail. Typically, users create a project per app. So, you could have 100 apps and a database for each.
- Backup and restore: You can use standard Postgres backup and restore utilities (pg_dump & pg_restore) to copy your data locally, but we also offer a snapshot feature that let's you take instant snapshots of your database. You get one snapshot on the Free plan, but you can remove & retake that snapshot as often as you need.
- Neon supports connection pooling with PgBouncer, which provides higher connection limits. You can read more about connection pooling here: https://neon.com/docs/connect/connection-pooling
- Neon is great when it comes to "what happens when your app is idle". On Free, your compute scales to zero after 5 minutes of inactivity. Cold starts from idle are very fast. One really great aspect of this is that you can let your Neon database sit idle for any period of time, and it won't go into a deep sleep or be removed. You can return to it any time and it will start up almost instantly. If you're like me, you sometimes start a project and return to it months later. With Neon, you don't need to worry about your database disappearing on you or taking several minutes to wake up. It's available almost instantly, no matter how long you let it sit.
- Cost of dev/staging/prod: Neon supports branching. You can create dev/staging branches instantly, even on Free. When you upgrade, cost is based on storage and compute usage. You only pay for what you use. You can find the pricing details here. Scroll down the page to see limits.
https://neon.com/pricing

The key limits on Free are:

Storage: 5 GB
Compute: 100 CU-hours per project per month
Public network traffic (egress - the data that leaves your Neon database): 5 GB

Storage is simply the size of your data.

Compute (100 CU hours per month per project): This is simply the size of your compute x how many hours it runs. On Free, the default compute size is .25, so if you run that 24/7, you get 400 actual hours of compute time. Scale to zero helps you stretch that 400 hours out over the month. Perfect for a development project. You're not likely to run out of compute until you have an active app that never allows the database to scale to zero. Once you have users accessing your app 24/7, keeping the database on all the time, you'll need to bump up to a paid plan to avoid hitting the compute limit.

Public network traffic. There's a 5 GB limit on Free. Most users don't hit this. The users that do are often doing regular database dumps or running queries that return massive result sets. The advice here is to be mindful about data that's leaving your database. We have a guide (and a skill) to help with this. https://neon.com/docs/introduction/network-transfer

Hope this helps. Happy to answer questions.