The only real weakness I see in the stack is Terraform. The elephant in the room is CloudFormation, and being built in Golang, Terraform is bounded by the functionality of Hashicorp's own AWS client lib (https://github.com/mitchellh/goamz), which hugely (and inevitably, given it's not a blessed 3rd-party library like boto) lags the official AWS clients (compare to e.g. https://github.com/aws/aws-sdk-java). It's going to take something radical for Terraform to be relevant to sophisticated AWS users.