Building
Enterprise
Platforms at Scale
10+ years of enterprise platform development — from monolithic to microservices. Specialized in Java/Spring Boot backend and React frontend for financial and public sector systems. Based in Seoul — open to European opportunities.
Who I Am
Location
Seoul, South Korea
Availability
Open to Remote (EU)
Languages
Korean (Native) · English (Professional)
Focus
Java · Spring Boot · React · MSA
I'm a senior full-stack developer with 10+ years of experience building enterprise platforms for Korean financial institutions and public sector. My most impactful project was transforming IBK Industrial Bank's investment platform from monolithic architecture to microservices, achieving 70% login speed improvement.
What sets me apart is my ability to bridge the gap between legacy enterprise systems and modern architecture. With deep expertise in both Java/Spring Boot backend and React frontend, I deliver end-to-end solutions — from MSA architecture design and API development to responsive UI implementation and CI/CD pipeline automation.
Development Philosophy
Architecture-Driven Thinking
I approach every project by understanding the system as a whole first — analyzing AS-IS architecture, identifying bottlenecks, and designing TO-BE solutions that scale. My MSA transformation of IBK BOX exemplifies this methodology.
Full-Stack Ownership
From React frontend to Spring Boot backend, from database optimization to CI/CD pipeline setup — I take end-to-end responsibility. This holistic view enables me to make better architectural decisions at every layer.
Performance as a Feature
I treat performance optimization as a core deliverable, not an afterthought. Using monitoring tools like Jennifer APM, I identify bottlenecks through data — reducing IBK BOX login time from 20s to 5s through systematic analysis.
Monolithic → MSA
Platform Modernization
A complete transformation of IBK Industrial Bank's enterprise investment platform from monolithic architecture to microservices — achieving 70% login speed improvement and enabling independent service deployment with CI/CD automation.
The Problem
IBK BOX platform was built on ExBuilder with Monolithic architecture and Server-Side Rendering. Login times exceeded 20 seconds. The system suffered from tight coupling, slow deployment cycles, and limited scalability.
Modernization Roadmap — 4 Major Phases (Aug 2024 - Dec 2025)
MSA Architecture Transformation
- →Analyzed AS-IS monolithic architecture: ExBuilder + JSP SSR with tight coupling, no CI/CD, complex procedural deployment
- →Designed TO-BE MSA with independent service deployment, separation of concerns (React SPA + Spring Boot REST API)
- →Built Gateway middleware with JWT parsing for forwarding user identity across microservices
- →Migrated Spring Legacy XML configuration to Spring Boot auto-configuration
- →Planned phased transition from monolithic to distributed system
Outcome
Microservices-ready architecture with independent deployment capability
Tools Used
Measured Results
Login Speed
Before
~20s
After
~5s
Architecture
Before
Monolithic
After
MSA
Mobile Dev Teams
Before
3 Teams
After
1 Team
Deployment
Before
Manual
After
Automated
Key Technical Decisions & Rationale
Decision
React SPA over JSP/SSR
Separation of concerns enables frontend and backend teams to work independently. React components are reusable across web and mobile (React Native WebView). Independent deployment decouples frontend changes from backend release cycles.
Trade-off Acknowledged
Initial learning curve for team experienced in JSP/SSR paradigm. Requires frontend state management discipline.
Decision
Spring Boot over Spring Legacy
Auto-configuration eliminates XML hell (web.xml, context-*.xml, property file chaos). Embedded WAS (Tomcat in Jar) ensures environment consistency from dev to production. Spring Boot Starters prevent Jar Hell and dependency conflicts.
Trade-off Acknowledged
Required systematic migration of existing XML configurations and testing of auto-configuration overrides.
Decision
JWT Gateway Middleware
Centralized authentication across MSA services. Gateway parses JWT and forwards user identity via headers to all downstream services. Eliminates N-way SSO complexity and reduces session database load.
Trade-off Acknowledged
Gateway becomes critical infrastructure (single point of failure mitigated with load balancing and circuit breakers).
Selected Work
IBK BOX Platform Modernization
Enterprise SaaS✦ Monolithic → MSA with 70% login speed improvement
Shinhan NewSOL Hybrid Chatbot
Hybrid App / FinTech✦ OTA deployment + JS Bridge for Korea's #1 banking app
AICA — Gwangju AI Industrial Platform
Gov't AI Platform / Frontend Lead✦ Frontend Lead — 90+ pages, dynamic router, Storybook design system
CESCO Food Label Consulting Platform
B2B Platform / Food Safety✦ WebSocket real-time consulting + 500MB SFTP for food safety B2B
Early Career — Enterprise SI (2014–2022)
7y 8m SI Experience✦ 19 SI projects — KB Bank, Korean Air, Samsung SDS, KOICA
Technical Expertise
Five filled squares = Expert (production use). Four = Advanced. Three = Proficient.
Backend
Primary expertise, 10+ years
Frontend
Modern UI development
Database
Enterprise data management
Architecture
System design & patterns
DevOps & Tools
CI/CD & monitoring
Mobile & Cross-Platform
Hybrid app development
Note on Architecture Skills: My experience spans the full transformation journey — from analyzing monolithic legacy systems to designing and implementing MSA architectures. Having worked on 20+ enterprise projects across banking, telecom, and public sector, I bring deep understanding of both legacy constraints and modern best practices.
Work History
Total Experience
10+ Years
Education
B.Ed. Physical Education
Harbin Normal University (하얼빈 사범대학), China
Inner Mongolia, Hailar
High School Diploma
Hailar No.3 High School (하이라얼 제3고등학교), Inner Mongolia, China
Certifications
정보처리기사 (Engineer Information Processing)
한국산업인력공단 (HRD Korea) · 2014
Senior Full-Stack Developer
Freelance / Contract
Specialized in enterprise platform modernization and full-stack development for major Korean financial institutions and government projects. Leading architecture transformation from monolithic to MSA systems.
Key Contributions
- →Led IBK BOX platform transformation from Monolithic to MSA, improving login speed by 70%
- →Built AI chatbot service for Shinhan Bank's SOL mobile app with React frontend and Java backend
- →Led development team for Gwangju AI Industrial Convergence admin platform
- →Developed CESCO's e-commerce and consulting platform with Vue.js and Spring Boot
Mid-Level Java Developer
Enterprise SI Projects
Worked on large-scale enterprise SI projects for major Korean corporations including KB Kookmin Bank, LG U+, Samsung SDS, and Korean Air. Responsible for backend API development, database optimization, and frontend implementation.
Key Contributions
- →Developed banking system features for KB Kookmin Bank and Daegu Bank
- →Built telecom service platforms for LG U+ with Java and Spring framework
- →Contributed to Samsung SDS enterprise solutions with full-stack capabilities
- →Delivered Korean Air's internal systems with focus on reliability and performance
Junior Java Developer
SI Companies (Seoul)
Started career in enterprise SI development, building websites and management systems for government institutions and cultural organizations. Gained foundational skills in Java ecosystem and database management.
Key Contributions
- →Built digital platforms for National Library of Korea and Korean Folk Village
- →Developed management systems for KOICA (Korea International Cooperation Agency)
- →Implemented frontend interfaces with HTML, CSS, JavaScript, and jQuery
- →Learned enterprise development practices including version control, code review, and deployment
Let's Work
Together
I'm currently open to full-stack developer positions, particularly with European companies. With 10+ years of enterprise experience in Java/Spring Boot and React, I bring proven expertise in platform modernization and MSA architecture.