Umar Idris

1. Schema Design: Normalize to 3NF first, then denormalize critical read paths. Use UUIDs for IDs, and separate transactional tables from reporting tables. 2. Indexing: Add indexes on foreign keys and frequently queried columns like user_id, transaction_date. Use partial indexes for active records. 3. Partitioning: Partition large tables like transactions by month to keep queries fast. 4. ORM with Spring Data JPA: Use JPA for CRUD but write native queries for complex reports. 5. Performance: Implement connection pooling with HikariCP, use batch inserts, and enable 2nd level caching with Redis. 6. Data Integrity: Enforce constraints at DB level, use transactions for money movement, and implement soft deletes for audit trails.