Pulumi sounds interesting. Spent 10 mins with their marketing website and I'm not very clear whether it is a standalone set of libraries, or do they only work in conjunction with their cloud services. Do you know?
The only (minor) problem that I've seen in it is that the JavaScript/TypeScript support seems more mature and featureful than the other backends. So, I'll simply use that.
Looks like they actually might have added locking recently with https://github.com/pulumi/pulumi/pull/2697 but I haven't looked deeply