Sure — we were building a new checkout flow and the team needed engagement metrics. I worked closely with the PM and DS to understand what they needed, then designed a star schema with a fact table for checkout events and dimensions for users and products. I wrote the ETL pipeline in Spark, added data quality checks, and deployed to production. The DS team was able to run their analysis the next day. The pipeline ran reliably for over a year with no major incidents.
Our DS partner kept pulling raw event tables manually every sprint to measure checkout funnel drop-off — no pipeline existed. I went to the PM directly, asked what decisions she needed the data to support, and learned she was tracking whether a redesigned payment step reduced abandonment. I defined three metrics myself — step completion rate, abandonment rate by device, and time-to-purchase — then designed a star schema around them before writing a single query. I brought the schema back to the DS and PM for sign-off, built the Spark ETL with SLA monitoring, and shipped to production. Abandonment rate dropped fourteen percent in the first measurement cycle, and the pipeline became the team's canonical checkout dataset.