Ah I see. Today, you will configure a work pool on Prefect Cloud and then run a Prefect worker somewhere in your environment that will take flows from that work pool and submit them for execution in your environment.
The feature we're working on today is a serverless version of that worker that will submit work for execution in your environment without you needing to run a persistent service. However, Prefect Cloud will not execute your code in its environment, it will submit it to an execution environment that you provide to us.
If you're in AWS, you will be able to have Prefect Cloud directly schedule work to AWS ECS in your project. The scheduling and orchestration happens in Prefect Cloud, and the execution happens in your AWS ECS. The big breakthrough here is that you won't need to run a persistent Prefect Worker on your side.