Resume — Hen Heang | Backend / AX Software Engineer

PROFESSIONAL SUMMARY

Backend / AX Software Engineer with 2+ years of experience building Java and Spring Boot applications in Cambodian and Korean enterprise environments. Experienced in REST APIs, MyBatis, Spring Security, PostgreSQL, Oracle, and SQL-driven business logic for financial and B2B platforms. I have integrated practical LLM-powered product features and use Claude Code and Codex for AI-assisted planning, analysis, implementation, review, testing, and documentation. I am learning Agent Harness, MCP, guardrail, evaluation, and observability concepts through structured practice; these are growth areas, not claims of production-scale agent infrastructure experience.

TECHNICAL SKILLS

Backend: Java, Spring Boot, MyBatis, Spring Security, REST APIs, Maven

Database: PostgreSQL, Oracle, MySQL, SQL Optimization, Schema Design

AI & Developer Productivity: Claude Code, Codex, Google Gemini API, OpenAI API, LLM Integration, Prompt Design, AI-Assisted Code Review

Frontend: Next.js, React, TypeScript, JavaScript, jQuery, Tailwind CSS

Tools & Delivery: Git, GitHub, Postman, Swagger, Vercel, Railway

PROFESSIONAL EXPERIENCE

Backend Developer (Java & Spring Boot) — Bizplay

October 2025 – Present

Seoul, South Korea

Implement Java and MyBatis services and SQL queries against an Oracle database for government-facing financial systems.
Build supporting frontend pages with HTML, CSS, and JavaScript (jQuery) for internal enterprise tools.
Maintain and improve the stability of enterprise web applications in a Korean enterprise environment.
Collaborate with cross-functional teams following Korean enterprise development conventions.

Technologies: Java, MyBatis, Oracle, JavaScript, jQuery, HTML/CSS

Software Engineer — KOSIGN (Korea Software Innovation Global Network)

January 2024 – October 2025

Phnom Penh, Cambodia

Designed and developed REST APIs with Spring Boot and MyBatis for an enterprise B2B billing platform integrated with Vietnamese banking systems.
Designed PostgreSQL schemas and optimized query performance for high-volume transactions.
Implemented Spring Security with JWT authentication to secure enterprise-grade APIs.
Integrated Zalo, SMS, and Telegram delivery channels for transactional notifications.
Collaborated daily with Korean development teams on architecture design and code reviews.

Technologies: Java 8+, Spring Boot, Spring Security, PostgreSQL, MyBatis, Next.js, TypeScript

SELECTED PROJECTS

H-Phsar — Backend API

Technologies: Spring Boot 3, Java 17, MyBatis, PostgreSQL, WebSocket | github.com/Hen-Heang/h-phsar-api

Backend API for a B2B marketplace connecting distributors and retailers, built on Spring Boot 3 and PostgreSQL.

Designed the data model for stores, product catalogs, and carts, and implemented an order state machine with OTP-based verification.
Delivered real-time order notifications over WebSocket.

Money Flow — Backend API

Technologies: Next.js, TypeScript, Supabase, Google Gemini, Web Push | github.com/Hen-Heang/money-flow

Personal finance API and PWA on Supabase Postgres with row-level security, backed up daily to Neon.

Implemented budgeting, savings-goal, and recurring-transaction logic behind Postgres row-level security.
Added an AI chat endpoint over Google Gemini for spending insights and web-push budget alerts.

EDUCATION

Bachelor of Computer Science — Royal University of Phnom Penh

March 2020 – May 2024

Focused on software development, algorithms, and web technologies.

Full-Stack & Mobile Development Training — Korea Software HRD Center

July 2023 – April 2024

Intensive training in full-stack development and Android application development using Java and Kotlin.

Basic C++ Programming Certificate — ANT Technology Training Center

March 2021 – July 2021

Introduction to programming concepts and problem solving with C++.

LANGUAGES

Khmer — Native | English — Professional working proficiency | Korean — Elementary conversational