I Migrated a Real Production Codebase from Terraform to OpenTofu (Here's What Broke)

TL;DR: Migrating a standard AWS Terraform codebase to OpenTofu took half a day, most of which was CI pipeline updates. The S3 native locking alone made it worth it. The Problem I've been writing Terraform since version 0.8. Watched it grow from a scrappy infrastructure tool into the de-facto standard for cloud automation. I've migrated teams from CloudFormation to Terraform, written custom providers, debugged state corruption at 2 AM. Terraform is baked into how I think about infrastructure. So when HashiCorp switched to the Business Source License in August 2023, I did what most practitioners did: I shrugged, bookmarked the OpenTofu repo, and went back to building. That bookmark sat there for two years. The BSL doesn't prevent you from using Terraform. It prevents you from building a product or service that's "substantially similar" to Terraform Cloud or Terraform Enterprise. For most teams running internal infrastructure, the risk is low. But once you're building a platform team that