Similar idea to https://www.pulumi.com/, but from AWS and with less languages so far. I'm a fan of being able to use full languages to build declarative representations of the infra I want, as languages like Terraform's HCL can break down if you try to do to much modularity with them.
AFAICT it's good that there are several teams implementing this pattern (not just one startup), but Pulumi is probably more battleworn for now.