Hadi Shamoun

Infrastructure and Deployment
• Provisioned and managed 3 Proxmox servers, one per branch, each running dedicated Linux VMs for the React.js
frontend, NestJS backend, and MySQL database — fully self-hosted with no cloud dependency.
• Configured secure cross-border remote access using Tailscale (Lebanon) and ZeroTier (Syria), enabling staff across
two countries to access the platform without exposing public ports.
• Deployed and maintained a live production system serving 19 active users across 3 branches; currently architecting a
real-time multi-server data synchronization solution.

Backend Development System Architecture
• security — designed and maintained as sole developer.
• Designed a normalized MySQL relational database schema using TypeORM across entities including customers,
suppliers, items, branches, vouchers, and financial accounts, with full referential integrity.
• Implemented JWT-based authentication with a granular RBAC engine enforcing feature-level permissions per user,
using custom NestJS guards and decorators.
• Built a real-time WebSocket layer using Socket.io for live cross-branch data synchronization and security alerts;
engineered a multi-currency engine with dynamic exchange rate management.
POS, Inventory Management, and Financial Modules
• Built a complete POS system covering invoice creation, delivery notes, pricing tables, and real-time cross-branch
inventory lookup — processing over 3, 000 invoices within the first 3.5 months.
• Developed multi-branch inventory management for a $2-3M product portfolio, including stock entries, inter-branch
transfers, physical stock counts, automated discrepancy detection, and full audit trails.
• Built a full accounting suite including chart of accounts, general journal, payment/receipt vouchers, cash collections
reconciliation, accounts receivable, and purchase invoicing with a proforma cost estimator.
• Delivered reporting dashboards covering sales audit, inventory audit, stock totals, trial balance, profitability reports, and
customer activity — filterable by branch and date range.
Business Analysis and Stakeholder Engagement
• Served as sole liaison between business stakeholders and the development team — conducted requirements gathering
sessions with company owners and branch managers across Lebanon and Syria.
• Replaced a failing Office-based legacy system; conducted UAT across all 3 branches and delivered a fully bilingual
Arabic/English interface with dynamic language switching.

Full-Stack Developer and Business Analyst at Infinity for Trading, where I designed, built, and deployed a production ERP/POS system from scratch. I developed the React.js frontend, NestJS/TypeScript backend, and MySQL database using TypeORM, JWT authentication, and role-based access control.

My responsibilities included building modules for invoicing, inventory management, accounting, payment and receipt vouchers, cash collections, purchasing, reporting dashboards, customer/supplier management, and multi-branch operations. I also handled deployment and infrastructure by setting up Linux VMs on Proxmox servers, configuring frontend, backend, and database environments, and enabling secure remote access using Tailscale and ZeroTier.