Engineered for Production. Tested with Real Data.
A collection of production applications, operations research solvers, and analytics platforms built and deployed by David Gao to automate multi-facility retail and enterprise operations.
Inventory & Replenishment ERP
Production ERP web application managing ingredients, recipes, and multi-facility replenishment. Features Bill-of-Materials (BOM) consumption conversion, automated PO creation, supplier grouping, and physical audit reconciliation.
Shift & Constraint Optimizer
Mathematical constraint programming solver in Python using Google OR-Tools CP-SAT. Solves globally optimal weekly schedules across 10 locations and 50+ staff in under 3 minutes, honoring 12-hour rest intervals, coverage, and labor laws.
Multi-Location Staff Schedule
Production employee schedule application serving 50+ staff across 10 European retail stores. Provides mobile-responsive shift lookup, branch location routing, and shift hour tracking with instant employee switching.
Retail Analytics & Forecasting Dashboard
Client-side business intelligence dashboard rendering 2 years of daily transactional data. Computes gross margin, AOV, hourly traffic heatmaps, customer loyalty retention, and top product basket pairings.