Is there a reason in principle that given this program: https://gist.github.com/jen20/27ed06a57d2a60af2f909cb3882f5277 the subnets can’t be created in parallel?

We should definitely be able to create in parallel. We don't yet fully parallelize CRUD operations based on the DAG, however we now do track proper dependency information correctly (this has been tough to figure out in a real language, but the promise-like

Output<T>

abstraction now gives us everything we need here). @incalculable-sundown-82514 has been chipping away at landing this for real, and https://github.com/pulumi/pulumi/issues/106 tracks the final steps.

👍, good to know it’s coming