No matter how you like to participate in developer communities, Pulumi wants to meet you there. If you want to meet other Pulumi users to share use-cases and best practices, contribute code or documentation, see us at an event, or just tell a story about something cool you did with Pulumi, you are part of our community.

Pulumi Community

and there's only one C# file -- called `MyStack.cs`. Presumably there should be one for every _stack_?

no. you only need one file, stacks are reusable instances of configuration. I'd recommend watching this video if you can:

<https://www.youtube.com/watch?v=YfdFxae8Bxc>