Na Gyu-tae

Senior Back-End Developer
Seoul, KR.

About

Highly accomplished Senior Back-End Developer with 7+ years of experience in designing, developing, and optimizing scalable systems across diverse industries including e-commerce, travel tech, and aerospace. Proven expertise in Kotlin, Spring Boot, Node.js, and AWS cloud architecture, with a strong track record of successful system migrations, performance enhancements, and robust API development that directly contributed to business growth and operational efficiency.

Work

PAP
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Back-End Developer

Seoul, Seoul, Korea (Republic of)

Summary

Contributed as a Back-End Developer, focusing on maintaining and evolving server-side applications within the development team.

Highlights

Developed and maintained robust APIs for various services, ensuring high availability and seamless data flow.

Collaborated with front-end teams to integrate new features and enhance existing functionalities, improving overall system performance.

Participated in code reviews and adopted best practices to ensure code quality and maintainability across projects.

VCNC
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Internal Team Development Leader (Back-End)

Seoul, Seoul, Korea (Republic of)

Summary

Led back-end development initiatives, overseeing critical system migrations, performance optimizations, and new feature development for internal and customer-facing applications.

Highlights

Led the migration of a legacy Node.js server to a Kotlin-based architecture for the Chic Customer App API, enhancing API stability by isolating domain failures and increasing registered listings from 20,000 to 30,000.

Optimized image upload processes by refactoring MultipartFile parameters to image URLs and enabling direct downloads, reducing crawling server CPU utilization by 60% and significantly improving system stability.

Implemented AWS ElasticCache-Redis with Look Aside/Write Around strategies for the seller search API, improving response speed by caching product counts for 10 minutes and reducing database load.

Developed a used luxury goods inspection system, integrating Zebra barcode scanners and BIXOLON printers, which eliminated operational inefficiencies and reduced customer inquiries by providing real-time inspection progress.

Resolved critical Lazy Loading issues in Kotlin JPA by applying the `all-open` plugin, preventing server-wide downtime during traffic spikes and improving Read/Write database utilization across APIs.

Yellow Balloon (노랑풍선)
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OTA Team Back-End Developer

Seoul, Seoul, Korea (Republic of)

Summary

Developed and managed back-end systems for OTA operations, focusing on real-time monitoring, driver onboarding, and recruitment processes to enhance efficiency and service delivery.

Highlights

Developed a real-time monitoring system for driver supply and passenger demand, integrating Naver MAP and Inavi APIs to enable optimal dispatch and reduce dispatch failure rates by strategically relocating drivers.

Spearheaded the development of a driver onboarding system, automating manual document management processes (contracts, insurance, permits) and increasing driver registration rates through systematized data handling.

Implemented Terraform for the first time to automate cloud resource provisioning (including Amazon RDS), establishing a code-based infrastructure that ensured consistency and reliability for new projects.

Designed and implemented an automated file separation feature using AWS S3, Lambda, and PyPDF2, efficiently processing scanned paper documents for the driver onboarding system.

Systematized the driver recruitment process, migrating from Google Forms to a custom platform and integrating Kakao API for referrals, significantly improving the efficiency of applicant communication.

Heyum System (혜윰 시스템)
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Development Team Back-End Developer

Seoul, Seoul, Korea (Republic of)

Summary

Contributed as a Back-End Developer, building and enhancing various systems including flight schedule management, technical data management, and internal communication platforms.

Highlights

Developed APIs for real-time lowest airfare retrieval from airline systems and an admin feature to compare fares, enhancing price transparency for customers.

Created a keyword extraction system for Korean translations of English airfare rules, enabling efficient comparison and management of complex pricing regulations.

Implemented the KF-X TISS technical data management system for KAI, including a CAD drawing management solution with access control and document review functionalities.

Developed a departmental bulletin board within the drawing management system, featuring access control, post management APIs, and drag-and-drop file upload capabilities to streamline internal communication.

Built a system risk issue visualization tool, collecting system errors and displaying weighted issue data from the last 30 days using Kendo UI TreeMap, improving operational insights.

Languages

Korean
English

Skills

Programming Languages

Kotlin, Java, JavaScript, TypeScript, Python, Node.js.

Frameworks & Libraries

Spring Boot, Spring Framework, NestJs, Angular, NextJS, JPA, TypeORM, MyBatis, jQuery, Ajax, Kendo UI Framework.

Cloud Platforms & DevOps

AWS (S3, Lambda, EC2, RDS, BeanStalk, ElasticCache-Redis), Terraform, Firebase, Docker, Datadog, CI/CD Pipelines.

Databases

Oracle, MySQL, Redis.

APIs & Integrations

RESTful APIs, Naver MAP API, Inavi API, Kakao API, Docusign API, HTTP Communication, XML Unmarshalling.

Tools & Methodologies

Gradle, Git, Problem Solving, System Design, Performance Optimization, Data Processing, Microservices, Monolithic Migration, Caching Strategies (Look Aside, Write Around), Database Replication, PyPDF2.