Comprehensive operational guidance for Jemena's Databricks platform following 5-layer architecture (AWS Resources → Unity Catalog → Workspaces → Data Products → Governance Apps). Covers complete runbooks for adding workspaces, onboarding business units, modifying shared modules safely, terraform remote state patterns, GitLab HTTP backend, module vs stack decisions, Unity Catalog design (centralized metastore, catalog-per-BU-per-environment), 3-dimensional RBAC (functional×classification×compliance), metastore binding constraints (permanent, cannot rebind), deployment order WHY (immutable dependencies), state file coupling, blast radius calculations, and troubleshooting permission denied errors. Use when working with terraform, databricks-unity-catalog repo, databricks-workspaces repo, app-datahub-aws-infra repos, adding new workspaces or BUs, RBAC issues, catalog/schema operations, or state file management.