Worked on enhancing configuration validation in the nebari-dev/nebari repository, focusing on stabilizing the TerraformStateStage component. Addressed a complex bug where immutable field validation failed for non-Pydantic sub-schemas, which previously caused errors during custom configuration overrides. The solution involved refining backend logic in Python and YAML to correctly handle nested configurations, such as those found in jupyterhub overrides, ensuring that non-Pydantic models are processed without validation issues. Comprehensive tests were added to verify the new behavior and prevent regressions, resulting in more reliable configuration management and reduced deployment risk for users with advanced Terraform state requirements.