question, the https://www.pulumi.com/pricing/ plan comparasion, says that starter plan has "Up to 20 Project stacks" Does this means that a single project can have maximum 20 stacks, or that across all projects we can have maximum 20 stacks? Also on the free plan this is not specified, does the same limit applies or another?

@gentle-diamond-70147 can you help here?

It is 20 across all projects.

And there's no limit on free projects. There's no limit on stack outside of your Pulumi org either. You can have any number of stacks on self-managed backends (local, S3, etc.), and up to 20 within Pulumi's managed service.