Data cleaning using sql

Data cleaning using sql

Designed a star-schema data warehouse (5 dimension tables, 2 fact tables) and built an ETL pipeline to load and clean 8 raw CSV sources using staging tables, BULK INSERT, and a custom date-parsing function.

Performed data validation and statistical outlier detection (3-sigma rule) to ensure data quality.

Wrote 14+ SQL queries using CTEs, window functions, and joins to analyze revenue growth, return rates, and customer segmentation; built reusable views for reporting.