Monthly sales report for a retail chain, written entirely in PostgreSQL: revenue by store and category, basket size, and the share of revenue from the top 20% of products. Found that two stores had been double-counting returned items for six months.
Cleaned 18 months of exported support tickets with Power Query (duplicates, free-text categories, mixed date formats) and built a pivot-driven Excel dashboard: volume by cause, first-response time, and the backlog trend. Cut the weekly reporting from half a day to about 20 minutes.
Star schema over orders, deliveries and returns, with DAX measures for on-time delivery rate, return rate and cost per order. One scorecard page for managers, with drillthrough to the order level when a number looks off.
Compared three options for handling product returns (keep the call center, outsource, build a self-service portal) with ROI, NPV over three years and a sensitivity analysis on return volume. Wrote the two-page business case that went to the ops director.
Side project for a friend's physiotherapy practice: interviewed the three therapists and the receptionist, mapped the current booking process, and wrote the user stories and acceptance criteria for a simple online scheduling tool. The practice now uses a no-code tool built from that spec.
Business analyst for the patient-support team. I own the requirements for the ticketing tool, run the monthly KPI review with the support leads (SQL + Power BI), and wrote the business case that moved two support workflows to self-service.
Supported the e-commerce operations team: mapped the order-to-delivery process, maintained the weekly Excel reporting pack, and gathered requirements for the new returns portal with the product and logistics teams.
Four validated projects: SQL reporting, Excel and Power Query, Power BI, business case modeling.
Handled customer accounts and complaints for a regional paper supplier. Started tracking complaint causes in a spreadsheet, which became the team's first real reporting. That is how I got into data.