Teepakorn Kumvong · Backend & Full-Stack Engineer · Secure Systems · Open Source Developer

👨‍💻 About Me

Teepakorn Kumvong · aka ToeyAIYU · Bangkok, Thailand 🇹🇭

I'm a Computer Science graduate from Rajamangala University of Technology Tawan-Ok (RMUTTO) — currently working as a Backend Developer at S11 Group PCL and founder of MN Lizard Team, an open-source organization building tools like Aiyu Multi-Agent and PromSell POS CE. Focused on backend systems, secure runtime, and developer tooling.

🎓 Education & Background B.Sc. in Computer Science — RMUTTO, Chakrabongse Bhuvanarth Campus Focus Areas: Backend Architecture, Full-Stack Development, Secure Systems, AI Runtime Interests: Developer Tooling, Cloud Computing, Open Source 🎯 Current Focus 🏗️ Working on NestJS + gRPC microservices 🤖 Developing open-source AI agent tools 🦎 Maintaining MN Lizard Team — open-source org 🌱 Advancing Node.js & system design 🔐 Exploring DevSecOps & security hardening 📚 Researching image forgery detection

🏆 Quick Stats 💼 Current Role: Backend Developer @ S11 Group PCL 🚀 Founder & Lead: MN Lizard Team — Open-source organization 🤖 Open Source: Aiyu Multi-Agent & PromSell POS CE @ MN Lizard Team 🎓 Capstone: AI Deepfake Detection (83.1% accuracy) 🌐 DevOps: CI/CD, Docker, npm publishing, semantic versioning 📫 Get in Touch 📧 Email: teeprakorn.official@gmail.com 💼 LinkedIn: Teepakorn Kumvong 🐙 GitHub: teeprakorn1

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💼 Professional Experience

Backend Developer — S11 Group PCL | 2026–Present

S11 Group PCL (SET: S11) — A SET-listed financial institution and a leading player in Thailand's motorcycle hire-purchase market, operating nationwide through an extensive dealer network.

Building and maintaining NestJS microservices for internal business operations.

What I Build RESTful APIs and gRPC microservices with NestJS File storage system with S3 multipart upload and streaming Image processing pipeline (sharp, HEIC→WebP conversion) Authentication & authorization (JWT, Keycloak, API key guards) Circuit Breaker pattern for resilient inter-service communication

Tech Stack Runtime: Node.js, Bun (package manager & build) Framework: NestJS, gRPC + Protocol Buffers Storage: S3-compatible (MinIO/Garage), Redis Observability: OpenTelemetry, Sentry, SigNoz DevOps: Docker (multi-stage), GitLab CI/CD Patterns: Circuit Breaker, Feature Flags (FeatureHub)

Source code is proprietary and not publicly available.

Software Engineer Intern — Banzai (Thailand) Co., Ltd. | 2025

Banzai (Thailand) Co., Ltd. — A subsidiary of Banzai, Ltd. (Japan), a specialized trading company for automotive maintenance equipment, inspection tools, and after-sales services across Thailand.

Built a full-stack company website (Company Profile) with React and Express.js, including user management, product catalog, dashboard, and a Markdown-based content system.

What I Built Full-stack company website with React + Express.js Authentication & authorization (JWT + bcrypt + cookie-based sessions) File upload & image processing (multer memory storage + sharp) Security hardening (helmet, CORS, XSS prevention, rate limiting) Structured logging with winston (request, security, performance) SEO optimization (react-helmet-async + react-snap static generation) Markdown content management (react-markdown with sanitize)

Tech Stack Frontend: React, react-router-dom, axios, react-helmet-async, react-snap Backend: Express.js, JWT, bcrypt, cookie-parser Database: MySQL File: multer, sharp, file-type (magic bytes) Security: helmet, CORS, XSS, rate-limiter, geoip-lite Logging: winston, winston-daily-rotate-file Docs: Swagger UI, yamljs Email: nodemailer

Fieldwork with engineers — machinery installation, inspection, and maintenance at client sites.

Assistant Computer Engineer Intern — V.VATTANA Solution Engineering | 2021

V.VATTANA Solution Engineering Co., Ltd. — An engineering and manufacturing company based in Samut Prakan, specializing in industrial machinery design, PLC automation systems, and technical consulting for the manufacturing sector.

First exposure to industrial IT and embedded systems during vocational studies. Worked under senior engineers to learn the basics of automation and hardware programming.

• Assisted in PLC programming (ladder logic) for industrial machinery control systems
• Learned C++ embedded programming for microcontroller board control
• Supported on-site computer maintenance — hardware troubleshooting, OS installation, and network configuration at client factories
• Gained foundational understanding of industrial automation workflows and hands-on technical problem-solving

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🦎 MN Lizard Team

Open-source organization building practical software for local businesses and developers.

Founded to share the tools we build with the community. No fixed roadmap — if a project is worth building, we build it.

Featured Projects

Project	Tech	Description
Aiyu Multi-Agent	Node.js, TypeScript	Multi-agent AI runtime with 84+ agents, MCP integration, WebSocket streaming, multi-LLM failover (OpenAI, Claude, Groq, Ollama), and pluggable skill system via npm
PromSell POS CE	Flutter, Dart	Offline-first mobile POS with Drift SQLite. Sales, inventory, receipt management, PromptPay QR, VAT support, Thai/English live switching, and CSV backup/restore

→ Visit Organization Profile · Contributing Guide

Also founded and lead MN Lizard Team, an open-source organization building developer tools and practical software.

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🎓 Capstone Project

Student Activity Tracking with AI Deepfake Detection

2024–2025 | Rajamangala University of Technology Tawan-Ok (RMUTTO)

Full-stack platform for student activity management with photo verification (83.1% accuracy). Backend, web, mobile, and AI components deployed on Windows Server with Cloudflare CDN.

🌐 Side - Open Source

md2pdf-th

Personal open-source project — Markdown-to-PDF engine with Thai-aware typography. Auto-detects Thai text with smart font fallback, supports mixed-language documents, and runs as CLI, library, or NestJS module.

Features: Light/Dark themes, 3 built-in templates (resume, report, invoice), TOC, cover page, watermark, PDF merge, and Docker/Chromium support.

GitHub · npm

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🛠️ Technical Skills

💻 Languages & Frameworks

TypeScript · JavaScript · Python · C++ · SQL · Dart · Java · Kotlin

⚙️ Backend & Infrastructure

Category	Technologies
Backend	NestJS, Express.js, gRPC, REST, WebSocket
Databases	MySQL, Redis, Firebase, Drift (SQLite)
Storage	S3 (multipart, presigned URLs), local streaming
Auth	JWT, OAuth 2.0, Keycloak, API key guards
DevOps	Docker, GitLab CI/CD, GitHub Actions, npm publishing
Observability	OpenTelemetry, Sentry, SigNoz
Cloud	AWS S3, MinIO, Cloudflare CDN

🏗️ Architecture, AI & Security

Area	Skills
AI Runtime	Multi-agent orchestration, LLM failover (OpenAI, Claude, Groq, Ollama), MCP, tool sandboxing
Resilience	Circuit Breaker, Rate Limiting, Feature Flags
Testing	Jest, integration tests, compliance tests, load testing, security test cases
Security	JWT + API key guards, PII masking, path traversal prevention, XSS/rate limiting, Kali Linux
Patterns	Facade, Guard, Interceptor, DTO, Repository

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🎓 Academic Projects

🎓 BusIT+ (Capstone)	🚀 PM2.5 Monitor	🔮 DuangDee
Student Activity + AI Deepfake	Air Quality + ML Forecast	Fortune-Telling Multi-Platform
Flutter React TensorFlow	Flutter Python ML	Kotlin React Firebase
🔗 Backend · 💻 Web · 📱 Mobile · 🤖 AI	📱 Mobile · 💻 Web · 🔧 API	📱 Android · 💻 Web

🧑‍⚕️ Doctor Mgmt	🧠 Depression Screen	🐟 Betta E-Commerce
Patient-Doctor Appointments	Mental Health AI Screening	Thai Betta Fish Store
React Node.js MySQL	Kotlin Flask TensorFlow	ASP.NET SQL Server
💻 Frontend · 🔧 Backend	📱 App · 🤖 API	Repo

IoT Mini Farm
Smart Farm Automation
ESP32 C++ Blynk
🔗 Repo

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🏆 Achievements & Highlights

🏅 Achievement	📅 Year	🔗 Link
💼 Backend Developer @ S11 Group PCL — NestJS microservices (gRPC, S3, OTel)	2026–Present	Proprietary
🤖 Open Source (Org) — Aiyu Multi-Agent & PromSell POS CE @ MN Lizard Team	2024–Present	GitHub
📄 Open Source (Personal) — md2pdf-th — Thai-aware Markdown-to-PDF	2024–Present	GitHub · npm
🎓 Capstone Project — AI Deepfake Detection (83.1% accuracy)	2024–2025	Backend
🔬 Research Paper — Image Forgery Detection (under review)	2025	—
🥇 Gold Medal — OOP Competition — National level, Private Vocational Education Association of Thailand	2021	—

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🚀 Engineering Interests

• Backend systems & runtime architecture
• Developer tooling & extensible platforms
• Service resilience & observability
• Secure execution environments
• AI workflow orchestration

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┌──(toeyaiyu㉿github)-[~/profile]
└─$ echo "Thanks for visiting!"

💙 Teepakorn Kumvong · ToeyAIYU