Data Engineering Intern
HDFC Securities
Federated Query Lakehouse
- Build and operate a production federated query lakehouse on Docker, federating SQL across Apache Iceberg tables on AWS S3 and relational sources (Oracle, PostgreSQL) through a Trino coordinator-worker cluster with Apache Superset BI and Apache Ranger authorization.
- Deployed the stack to an air-gapped RHEL 8.8 production host with all images and RPMs version-pinned and pre-staged ahead of network cutoff; automated log rotation, resource alerting and backups via Cron.
- Cut Databricks compute spend by ~40% by routing reporting and ad-hoc analytical queries through Trino on the lakehouse instead of source systems and dedicated job clusters.
Revenue Reconciliation & Pipeline Rebuild
- Investigated a 2–3% revenue and turnover mismatch between the Oracle source and the gold layer, proving 543,354 duplicated rows in silver — a single full-day double-load affecting 18,175 clients, plus a scattered pattern across six other dates.
- Traced parallel gold-layer aggregation defects to raw order_ts and sub_product_type used as GROUP BY keys, SUM() applied to per-share price fields, and inconsistent grouping keys across three contract-note schemas.
- Validated a trade-key deduplication fix that realigned row count, quantity, revenue and turnover with the Oracle source from bronze through gold, verified using the pipeline’s own reporting formulas.
- Rebuilt the pipeline end to end in PySpark and Delta Lake — YAML-driven append-only bronze ingestion, silver deduplication and typing of ~70 columns, gold aggregation on eight normalized keys with quantity-weighted average pricing — orchestrated on Databricks Workflows and now live in production.