Reitse Eskens doesn’t need a server:
In my previous blog I wrote about the premium tier, the one that can be compared with the business critical tier. Now we’re moving away from the DTU models and back to what we DBA’ers really understand, cores, memory and disks. Before I’m going to dive into the limitations, there’s one thing you need to understand. The serverless tier is made for intermittent use. If you’re using the tier for more than 25% of the time (or about 183 hours per month), you’re better of going provisioned. This has nothing to do with performance but everything with cost. The tipping point of provisioned being cheaper is around 25% of the time.
There’s some solid advice on how to get the service to go to sleep but the bulk of the article revolves around performance.