Upgrading Our Infrastructure with OpenTofu

In September 2025, Matt Velez, a Site Reliability Engineer at TrueCar, detailed their transition from Terraform to OpenTofu, facilitated by Spacelift, following the change in Terraform's licensing to a closed-source model. This migration involved moving over 700 infrastructure stacks to OpenTofu due to its open-source nature and additional features like early variable evaluation, which helps prevent accidental regressions. Velez described the challenges of coordinating multiple versions and the benefits of using a monorepo to streamline the transition. OpenTofu's capacity to automatically determine state file configurations reduced user error, while Spacelift's integration with OpenTofu enabled a smooth transition. Velez commended Spacelift’s support throughout the process and expressed optimism about leveraging OpenTofu's features for future infrastructure improvements.