Fair warning, I’ve been in situations with Pulumi where destroying and recreating a “stack” is the only way to solve little intermittent bugs. Not sure what level of stability you’d want from a tool like this but it made me raise an eyebrow.

I understood it was basically Terraform under the hood...

I have little experience with either, do you find another tool more reliable?

I guess all of these tools are dependent on the consistency of the cloud provider APIs they're working with

We did evaluate pulumi. Our experience was that it basically gives you alternative, more error prone way to create terraform resource graph. Also while they claim to support python, it definitelly feels like second class citizen, it's not very idiomatic (more like almost-literal rewrite from the typescript).

So for time being we are sticking with terragrun&terraform combo.

But the concept of pulumi looks interesting and we will likely re-evaluate in a year or so to see if it has moved in the right direction.