mamura

- Built 5 data marts and 3 PySpark/Greenplum ETL pipelines over transaction and loyalty data of a national retailer; automated 140+ reports, cutting preparation time by 90%. - Improved and retrained a production customer-segmentation model (multiclass gradient boosting on aggregated behavioral features). Mentored a junior analyst who was later hired full-time. - Ran 15 mobile-app A/B experiments (∼7% conversion uplift in key flows after rollout) and CVM campaigns by customer cluster; introduced a campaign design framework with automatic MDE pre-estimation.