Hi, I'm Đoàn Công Khoa.
Backend Developer Java / Spring Boot
Crafting resilient RESTful APIs, scalable microservices architectures, and high-performance backend systems with Java 21, Spring Boot, PostgreSQL, and RabbitMQ.
About Me
I am a Backend Developer and Software Engineering student at FPT University with hands-on internship experience at FPT Software. My core expertise centers on Java 21, Spring Boot, and scalable distributed architectures.
Throughout my 6-month internship at FPT Software and personal production-grade projects, I have architected microservices platforms, built resilient web crawlers, integrated asynchronous event-driven messaging with RabbitMQ, and processed automated SePay VietQR payment webhooks with idempotency guarantees.
I actively incorporate modern AI capabilities—including Google Gemini AI for automated ATS CV parsing—while ensuring solid software engineering practices: clean code, Dockerized container deployments, and reliable RESTful API standards.
Engineering Values
- Clean Architecture: Decoupled layers, testable logic, domain-driven boundaries.
- Pragmatic Optimization: Caching strategies, indexing, and connection pooling.
- Documented & Tested: OpenAPI/Swagger specs and reliable unit tests.
Work Experience
Full-Stack Developer Intern — FPT Software
Contributed to enterprise project management workflows, automated payment processing pipelines, and high-performance frontend state architecture.
- ▸ Integrated SePay VietQR Payment: Implemented automated VietQR payment workflows for account tier upgrades and AI quotas, with webhook idempotency checks to prevent double processing.
- ▸ Built & Optimized Kanban Board: Developed an interactive board using @dnd-kit, cutting database writes from O(n) to O(1) via midpoint orderIndex calculation and eliminating UI drag lag.
- ▸ Frontend Auth & State Management: Structured React frontend using Zustand for centralized state, Axios JWT interceptors, and protected routes with HTTP-Only Cookie authentication.
Technical Skills
Languages & Frameworks
Databases & Architecture
DevOps & Tools
DevOps & Integrations
Featured Projects
Engineered for Reliability & Scale
JobRadar — Microservices AI Job Aggregator & ATS Platform
A distributed microservices ecosystem that aggregates IT job postings, performs intelligent ATS resume analysis via Google Gemini AI, and processes automated payment webhooks.
- ✔ Microservices Architecture: Architected a decoupled system comprising API Gateway, Auth, Job, Crawler, and Notification services with Docker and JWT security.
- ✔ Multi-Source Web Crawler: Built an automated crawler using the Strategy Pattern, JSoup, FlareSolverr, and SHA-256 deduplication to prevent duplicate postings.
- ✔ AI & Event Messaging: Integrated Google Gemini AI for ATS CV parsing, RabbitMQ for asynchronous job alert delivery, and SePay QR payment webhooks.
WebForSaler — Real Estate Management & Lead Generation Platform
Full-stack commercial real estate platform featuring dynamic unit price calculations, multi-criteria property filtering, and high-throughput asynchronous lead capture pipelines.
- ✔ Full-Stack Real Estate Platform: Developed complete property listing solution with dynamic unit price calculations and multi-criteria advanced filtering.
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Asynchronous Lead Processing: Built an event-driven lead capture pipeline using Spring
@Asyncand Webhooks to dispatch real-time agent notifications and automated customer auto-replies. - ✔ Admin CMS & Reliability: Implemented rich-text blogging CMS, Soft-Delete data protection, Cloudinary CDN asset hosting, and 60-day automated cleanup Cron jobs.
Education & Certifications
Bachelor of Software Engineering
Formal Computer Science & Software Engineering curriculum. Grounded in rigorous algorithm analysis, object-oriented design patterns, distributed system architecture, and relational database performance.
IELTS 5.0 Equivalent
Official English proficiency qualification accredited by FPT University's international academic curriculum. Demonstrates confident comprehension of technical documentation, architectural RFCs, and collaborative teamwork in international settings.
Software Development Lifecycle (SDLC)
Agile methodologies, Lean development, engineering practices for quality software, Kanban principles, and architecture trade-off analysis.
Core Java for Beginners
Foundations of Java 21, multithreading, class hierarchies, Java Generics, Collections Framework, and GoF Design Patterns.
Web Applications for Everybody
Relational database design, structured SQL queries, data modeling, database applications in PHP/MySQL, and JSON asynchronous exchange.
Web Design for Everybody
Syntactically correct HTML5 and CSS3, DOM scripting with JavaScript, responsive design patterns, and WCAG accessibility standards.
User Experience Research & Design
User-centered design principles, qualitative user needs analysis, interactive wireframing, rapid prototyping, and usability evaluation.
Academic Skills for University Success
Rigorous critical thinking, problem-solving methodologies, information & digital literacy, academic research, and logical reasoning.
Let's discuss your next engineering challenge.
I am actively seeking full-time Backend Engineering roles and international freelance contracts. Whether you have a project to launch or a team position to fill, feel free to send a message!