-Design overall data architecture (lakehouse / medallion)
-Decide data modeling standards (facts, dimensions, naming)
-Own warehouse/lakehouse strategy (BigQuery / Snowflake / Redshift / Databricks)
-Lead Spark strategy and performance optimization
-Review PRs, enforce code quality & best practices
-Define data quality rules, SLAs, backfill strategy Own security design (IAM/RBAC, PII handling)
-Guide CI/CD, branching strategy, release process
-Cost optimization & capacity planning
-Mentor mid-level engineers