# Product Strategy & Requirements > Selected work demonstrating this service. - [Drove brand engagement and loyalty by 100% through market trend analysis and consumer behavior insights.](https://data.engineer.company/portfolio/drove-brand-engagement-and-loyalty-by-100-through-2/) - [Optimized forecasting and investment strategies for 11 electricity grid operators, driving operational efficiency through data‑driven GIS solutions.](https://data.engineer.company/portfolio/optimized-forecasting-and-investment-strategies-for-11-electricity-27/) - [Gathered and analyzed business requirements to translate into actionable features and user stories aligned with data governance standards.](https://data.engineer.company/portfolio/gathered-and-analyzed-business-requirements-to-translate-into-31/) - [Developed a Data Analytics reporting system, increasing quarterly software revenue by 400% through Python‑based PDF reports.](https://data.engineer.company/portfolio/developed-a-data-analytics-reporting-system-increasing-quarterly-44/) - [Designed a time‑management and reporting system that remained in production use for years without significant modification.](https://data.engineer.company/portfolio/designed-a-time-management-and-reporting-system-that-88/) - [Built the payments and entitlements layer — Stripe alongside Apple and Google in‑app purchase — gating the directory, search and export through an 11‑table access model checked on the server.](https://data.engineer.company/portfolio/built-the-payments-and-entitlements-layer-96/) - [Built the loyalty and reputation system — 67 functions over a 31‑table ledger, with leagues, badges and a redemption shop — taking a row lock on the balance to close the double‑spend window.](https://data.engineer.company/portfolio/built-the-loyalty-and-reputation-system-105/) - [Built the hiring marketplace and the seafarer career workspace — 151 stored functions across 48 tables — covering vacancies, applications, certificates, rank progression and verified sea time.](https://data.engineer.company/portfolio/built-the-hiring-marketplace-and-career-workspace-107/)