As mentioned in the other comment, the most commonly used providers for terraform are "bridged" to pulumi, so the maturity is nearly identical to Terraform. I don't really use Pulumi's pre-built modules (crossroads), but I don't find I've ever missed them.
I really like both Pulumi and Terraform (which I also used in production for hundreds of modules for a few years), which it seems like isn't always a popular opinion on HN, but I have and you absolutely can run either tool in production just fine.
My slight preference is for Pulumi because I get slightly more willing assistance from devs on our team to reach in and change something in infra-land if they need to while working on app code.
We do still use some Pulumi and some Terraform, and they play really nicely together: https://transcend.io/blog/use-terraform-pulumi-together-migr...