- Minimum 6 years of relevant experience in writing production-grade SQL using CTEs, window functions, and set-based processing.
- Ensure SQL code is readable, testable, reusable, and version-controlled (peer-reviewed via PRs).
- Optimise PostgreSQL performance through :
- Query tuning and execution plan analysis
- Indexing strategies
- Partitioning design and maintenance
- VACUUM/ANALYZE and table statistics management
- Locking and concurrency handling
- Use EXPLAIN (ANALYZE, BUFFERS) to diagnose slow queries and interpret :
- Join strategies (nested loop, hash, merge)
- Sort methods
- Buffer hits vs reads (I/O hotspots)
- Design effective indexes (btree, hash, GiST, GIN), including composite indexes aligned to filters, joins, and sort order
- Apply index-friendly query patterns :
- Sargable predicates
- Avoiding functions on indexed columns where possible
- Minimising implicit casts and datatype mismatches
- Implement resilient pipelines with proper error handling, retry logic, idempotency, and reprocessing/backfill capability.