Spettrum

Pet Photo AI Transformation Service | May 2024 ~ Sep 2024 | Homepage

Joined a university startup team as a backend developer to develop a service that transforms pet photos using AI technology.

🛠 Tech Stack

Spring Boot, Java, MySQL, Redis, Docker, Nginx, GitHub Actions, JUnit, JWT

Problem: Database stored announcements and content in HTML format as single language only, making multilingual support impossible for global service expansion
Solution Process:
- Analyzed existing single-language table structures and defined multilingual support requirements
- Designed new database schema using composite primary key with ID and Locale
- Performed safe migration from single-language to multilingual structure without data loss
- Implemented automatic language detection logic using HTTP Content-Language header
- Developed management system to maintain consistency across language-specific content
Results: Completed Korean and English support establishing global service foundation, achieved CES 2025 participation

Problem: Manual verification of multilingual API response accuracy led to high risk of human errors during deployment and time-consuming language-specific content consistency validation
Solution Process:
- Designed test cases for multilingual API endpoint response validation
- Implemented automated verification logic for response data consistency based on Content-Language header changes
- Added validation tests for missing required fields and translation quality by language
- Integrated automated quality verification process into CI/CD pipeline for pre-deployment validation
Results: Significantly reduced multilingual-related bug occurrence rate during deployment and shortened quality verification time

Problem:
- Existing manual deployment causing service interruptions
- Long rollback process during deployment failures, severely degrading user experience
- Persistent risk of service failures due to human errors during deployment process
Solution Process:
- Designed traffic routing system using Nginx upstream module
- Implemented automated deployment workflow based on GitHub Actions and Shell Scripts
- Developed health check and automatic traffic switching mechanism between Blue/Green environments
- Built automatic rollback system for deployment failure detection
Results: Achieved zero-downtime deployment and rapid rollback capabilities for stable service operation

JWT-based Authentication System Standardization
- Integrated JWT verification logic into Spring Security Filter Chain
- Modularized token generation/verification/refresh logic as common components
- Implemented access control system based on user permissions
Unified CORS Policy Management
- Configured CORS allowance policies by frontend domain
- Optimized pre-flight requests to improve API response speed

Global Service Foundation: Enhanced international user accessibility through multilingual support
Zero-downtime Service: Stable service operation through Blue/Green deployment
Development Efficiency: Optimized deployment process through automated testing
System Stability: Established quality verification system through integration testing