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Java Developer

Java Developer • FPT IS & Microservices Architecture

Backend Developer with a solid foundation in Java, Spring Boot, and RESTful API design. Experienced in large-scale banking projects and building microservices architectures with Kafka, Redis, and Keycloak.

Primary Technical Stack
Java (Core, OOP) Spring Boot JPA / Hibernate PostgreSQL Apache Kafka Redis Docker & Keycloak

Featured Engineering Case Studies

Real systems highlighting architectural decisions, technical trade-offs, and measurable outcomes.

View All (2) →
Banking & Finance 11/2024 — Present • Java Developer at FPT IS

Enterprise Banking System & Approval Workflows

Multi-module enterprise core banking platform developed at FPT IS

Engineering Problem

Complex banking business modules required strict multi-level approval logic, standardized data mapping, file imports, and efficient error handling without sacrificing query performance.

Architected Solution

Developed modular Spring Boot microservices with Jmix (Vaadin) framework UI integration, optimized PostgreSQL queries using JPA/Hibernate, and enforced OpenAPI specifications.

TECHNICAL DECISION & RATIONALE
Adhered strictly to OpenAPI 3.0 API Design Standards: Ensured seamless contract agreement between backend API endpoints, QA testing pipelines, and business approval UI components.
JavaSpring BootJmix (Vaadin)PostgreSQLJPA/HibernateOpenAPI/SwaggerGit
Full Case Study (Architecture & Trade-offs) →
Microservices 09/2024 — 11/2024 • Lead Project Developer

Stock Watch Platform — Microservices & Real-Time Streaming

Event-driven real-time stock monitoring architecture with Kafka & Keycloak

Engineering Problem

High-frequency price feed updates flooded primary databases and delayed user notifications during volatile market periods.

Architected Solution

Architected separate API and data microservices using Spring Boot, streaming price updates with Apache Kafka, caching active ticks in Redis, and pushing updates via WebSockets.

TECHNICAL DECISION & RATIONALE
Applied Redis Cache Layer for Frequently Accessed Ticks: Reduced database query load by 30% while serving sub-millisecond price lookups.
JavaSpring BootApache KafkaRedisMongoDBPostgreSQLKeycloakDockerWebSockets
Full Case Study (Architecture & Trade-offs) →

Technical Arsenal & Core Competencies

Categorized technical depth across backend development, database systems, microservices, and DevOps tooling.

Programming & Frameworks

Core Java, Spring Boot microservices, Spring Security, and ORM frameworks.
Java (Core, OOP) Expert
Spring Boot Expert
JPA / Hibernate Expert
RESTful APIs Expert
Jmix (Vaadin) Advanced
Spring Security Advanced

Databases & Messaging

Relational databases, NoSQL stores, caching layers, and message brokers.
PostgreSQL Expert
MongoDB Advanced
Redis Caching Advanced
Apache Kafka Advanced

Security & DevOps Tools

OAuth2 authentication, containerization, and API documentation.
Keycloak (OAuth2) Advanced
Docker Advanced
OpenAPI / Swagger Expert
Git & Version Control Expert
Linux Environment Proficient

Web & Frontend Technologies

Client-side web interfaces and modern JavaScript frameworks.
JavaScript / HTML5 / CSS3 Proficient
React JS Proficient
Svelte & SvelteKit Advanced

Career History & Track Record

Engineering experience across enterprise banking modules, microservices, and API platforms.

Java Developer

FPT IS — Ho Chi Minh City, Vietnam
11/2024 — Present

Participating in developing enterprise-level banking systems with multiple core business modules.

  • Built and optimized RESTful APIs using Spring Boot following OpenAPI standards.
  • Developed multi-level approval workflows for complex banking business logic.
  • Designed and implemented complete CRUD logic, data mapping, file import, validation, and standardized error handling across modules.
  • Utilized PostgreSQL and JPA/Hibernate to optimize database queries and system throughput.
  • Collaborated effectively with QA, BA, and backend engineering teams to ensure software quality and delivery timelines.
JavaSpring BootJmix (Vaadin)PostgreSQLJPA/HibernateOpenAPI/SwaggerGit

Microservices Lead Developer (Side Project)

Stock Watch Platform — Ho Chi Minh City, Vietnam
09/2024 — 11/2024

Built a high-performance personal microservices project focused on real-time price streaming and transaction processing.

  • Designed microservices using Spring Boot, separating API gateway, data services, and streaming pipelines.
  • Integrated Apache Kafka for real-time market data streaming and WebSocket to push instant price updates to clients.
  • Applied Redis caching to reduce database load by 30% under high request volume.
  • Secured microservice communications and user authentication using Keycloak (OAuth2).
JavaSpring BootApache KafkaRedisMongoDBPostgreSQLKeycloakDockerWebSockets

Engineering Principles & Values

RESTful API & OpenAPI Standards

Designing clean, well-documented RESTful APIs using OpenAPI standards to ensure seamless integration between microservices, frontend applications, and third-party systems.

Enterprise Banking Reliability

Implementing multi-level approval workflows, data mapping, file import validation, and standardized error handling for enterprise-level banking systems.

Microservices & Real-Time Processing

Decoupling API and data services using Spring Boot, streaming real-time data with Apache Kafka, and optimizing performance with Redis caching.

Database & Query Optimization

Using PostgreSQL, JPA/Hibernate, and MongoDB effectively to optimize complex database queries, reduce latency, and lower server load.