[terrabitz]

Not the original commenter, but our team has recently been dealing with this exact thing. It depends on the specifics of your use case, architecture, etc., but there is a lot of value in keeping application Terraform code in the same repo as your applications. The main benefit is that it's a simpler developer experience to make infrastructure changes related to their specific app. You can still have a big repo with a bunch of internal modules and core infrastructure code, but having the apps have their own infrastructure code can lead to developers having more autonomy in the DevOps process.