Full-stack engineer — I build operational software that real teams run their day on.

• 📊 BudgetTracker — offline-first personal budget app for the Philippines (native Android, Kotlin + Compose)
• 📈 Trading System — honest backtesting + signals engine for US stocks & forex (Python)
• 📸 Y2K Editorial Booth — browser photobooth with real-time face stickers & live camera filters
• 🖥️ ITDashboard — internal IT-ops dashboard (helpdesk, assets, network monitoring) on Next.js + Prisma
• 🤖 agentic-os — a personal AI-assisted dev hub (code knowledge graphs + project memory)

Full-stack web · real-time messaging bots · role-based access control & auth · third-party/ERP integrations · data-layer migration · performance tuning · API design · deploy & ops

TypeScript · JavaScript · Python · Kotlin · C# · SQL · HTML/CSS

React · Next.js · NestJS · Express · Jetpack Compose · Prisma · Mongoose · Firebase · Zustand · WebRTC · GSAP · Framer Motion · MediaPipe

Node.js · Git · Docker · MongoDB · PostgreSQL · Vercel · Azure · pnpm · Gradle · SAP

Computerized maintenance-management system for a national manufacturing operation. Technicians, planners, and managers coordinate work orders across multiple plants from one dashboard. Shipped to production:

• Real-time technician workflow over Telegram — assign, accept/decline, live progress, photo-gated sign-off, multi-technician shared jobs, synced two-way with the web dashboard.
• Role-based access control — server-enforced auth, configurable role/permission taxonomy, break-glass super-admin recovery, anti-corruption guards.
• Multi-tier cost-approval engine — threshold-based approval chains with emergency-bypass rules and audit trail.
• Data-layer migration — moved source of truth from a fragile spreadsheet to MongoDB with write-through mirror + outage fallback.
• SAP Goods-Issue integration + performance work — cut technician save latency ~7s → ~1.1s; fixed a cache/circuit-breaker bug masking correct data in production.

Client code is proprietary — this describes my contribution, not a source release.

📂 Full case studies → project-showcase

• Email: jason.guijo2160@gmail.com
• Open to full-stack / backend roles