Languages
Java / TypeScript / JavaScript / Python / Kotlin / SQL
Software Engineer
Hi, I'm Kongsun.
Over six years of software engineering experience, with a focus on backend systems, AI-augmented development, and product design.
Open to select work
Melbourne / Remote
Capabilities
Skills
Systems
Spring Boot / Node.js / PostgreSQL / Redis / Kafka / Docker
Product
Astro / Next.js / React / React Native / Flutter / Tailwind CSS
Infrastructure
AWS / Azure / Linux / GitLab CI/CD / Jenkins / Oracle
2019—Now
Experience
- Led a team of 5+ engineers to develop a fintech service using Java and Spring boot framework, Postgresql, and Oracle DB, processing $3M in transacitons monthly.
- Containerized legacy application stack using Docker, replacing error-prone manual deployments with a consistent, repeatable release process.
- Integrated 6+ payment channels including Alipay, UnionPay, Bakong National Payment System, SmartVista, telecom top-up, and internal bill payment systems into a unified platform.
- Boosted reliability and performance of a 50,000+ daily transaction pipeline via Redis caching, query optimization, and code profiling, eliminating duplicates, and sustaining 99.9% uptime.
- Engineered responsive admin panels and web platforms for user management and internal operations using Next.js, Ant Design, and Tailwind CSS.
- Developed an automated web scraping bot with Puppeteer and Node.js, eliminating manual data collection workflows.
- Managed application deployments on AWS EC2 and bare-metal servers via PM2, and owned end-to-end mobile release pipelines for both Google Play and Apple App Store.
- Led full-cycle software development projects, from planning and design through development, testing, deployment, and maintenance.
- Maintained a Java-based fintech e-money platform (Spring Boot & Dropwizard) serving 100,000+ daily users, ensuring high availability and consistent payment system performance.
- Expanded fintech platform capabilities by implemented new features and third-party integrations for bill payment and mobile airtime top-up services.
- Guided external partners through API integration as a provider, managed new partner onboarding configurations, and administered on-premise server deployments.
- Developed and maintained mobile applications across React Native, Flutter, and Android native stacks, contributing to both new feature development and ongoing production app maintenance.