Hi, I'm Duy 👋

🛠️ Tech Stack

Languages

TypeScriptC#JavaScriptSQL

Frontend

Next.jsReacttRPCReact QueryZustandZodTailwind CSSRadix UIAnt Design

Mobile

React NativeReduxFirebase

Backend

NestJS.NETNode.jsSocket.IO

Data & Messaging

MongoDBPostgreSQLSQL ServerRedisRabbitMQKafkaElasticsearch

DevOps & Auth

DockerNginxIISPM2Keycloakk6

🚀 What I'm Good At

• Cross-platform architecture — Comfortable owning both NestJS (Node) and .NET (Clean Architecture / DDD), choosing the right tool per problem.
• Platform thinking — I build shared frameworks, engines, and libraries instead of one-off solutions.
• Distributed & event-driven systems — SQL + NoSQL + Redis + Kafka/RabbitMQ + GridFS, background jobs, observability, resilience.
• End-to-end type safety — tRPC + Zod + TypeScript from database to UI.
• Security & compliance — Keycloak SSO, fine-grained RBAC, JWT, digital signatures, audit logs.

⚙️ Deployment & SEO

• Windows Server (IIS): web.config URL rewrite, SPA fallback, ARR reverse proxy, iisnode
• Linux: Nginx reverse proxy (TLS, gzip, static cache, WebSocket proxy) + PM2 / systemd, Docker / docker-compose
• SEO: Next.js Metadata API, dynamic multilingual sitemaps with hreflang, robots, SSR/ISR, Core Web Vitals

🧩 Things I've Built

• Workflow Engine

  Multi-level document review/publishing state machine + low-code drag-and-drop workflow designer

• Collaborative Editor

  Real-time co-editing with Yjs (CRDT) + TipTap + WebSocket, live cursors, versioning, PDF/DOCX export

• Dynamic Form Engine

  Google Forms–style, JSON-configured forms with conditional logic, business-rule validation & Word mail-merge

• File Service

  MongoDB GridFS streaming storage for large files, versioning, watermarking, Dockerized

• Multi-tenant CMS / Portal

  Subdomain tenancy, page builder (GrapesJS), dashboard builder, OnlyOffice integration

• Modular .NET Platform

  E-gov ecosystem (e-office, e-invoice, e-sign, e-survey, VietQR, Vietnam Post) + self-built Util.* shared libraries

• Internal Starter Framework

  NestJS + Next.js boilerplate: base services (Mongo/Postgres), audit log, request context, custom RBAC

• SSO / IAM

  Centralized authentication with Keycloak + custom admin client

• Job Portal & University Recruitment

  Job-search and campus recruitment platform — job/company listings, applicant tracking, online interviews via Zoom, SEO-optimized (multilingual sitemaps, SSR/ISR)

• University Public Service Portal

  E-gov service portal for universities — dynamic procedure forms, online dossier submission, multi-tenant per institution

• E-Citizen Portal (Khánh Hòa Province)

  Provincial digital-citizen platform — public services, notifications, realtime updates, web + mobile

• E-Invoice System

  Electronic invoicing — invoice generation, QR code (VietQR), built on the modular .NET platform

• HRM System

  Human resource management — employees, departments, attendance, question bank, document management

• Mobile E-Gov Suite

  React Native apps: digital identity, e-office, e-notary — realtime SignalR, push, Fastlane CI