I‘m Jinjae Lee
Software Developer

I am a software engineer with 15 years of experience in backend development and system integration. I have worked on various projects in web services, payment systems, and API design, consistently delivering stable and reliable solutions.

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/ Experience

I've been developing backend systems since 2009

I have developed websites and various backend systems for mobile payment companies and online game companies, and have always carried out successful projects through the stability of the service.

Java
Spring Boot
MySQL
Git
AWS
Docker
Jenkins
Grafana
Sentry
HTML
JavaScript
MSSQL
-2009
Years of experience
12
Successful projects

Payment Systems

Developed robust payment gateways and integration systems

Game Commerce Platforms

Built scalable game commerce platforms and services

API Development

Designed and implemented RESTful APIs

Web Services

Led backend development of web shop site and event landing page

SQL

Design and implementation of data schema for payments, settlements and analytics

Batch

Developed Spring Batch systems for payment processing, data extraction, and automated notifications

Monitoring

Developed monitoring systems using Grafana, Pinpoint, Sentry

Career History

2017.05 - 2024.08

Kakao Games Europe B.V

Backend Engineer

Developed and maintained web store platforms for Black Desert, Elyon, and ArcheAge. Implemented payment systems and managed backend services for multiple game titles.

Netherlands

2009.02 - 2017.01

Danal Co., Ltd.

Web Developer

Developed mobile payment services and portal systems. Led the renewal project of Danalpay website and developed BilltoMobile portal.

Republic of Korea

Projects

2024
Kakao Games Europe B.V
Web

Guardian Tales Twitch Drops Web Service

Developed Twitch account integration and reward distribution system

  • Developed backend services for Twitch account integration
  • Integrated Guardian Tales login with Twitch login system
  • Implemented in-game item delivery API
  • Built statistics dashboard using Grafana
JavaSpring BootAWSJenkinsMySQLTwitchGrafana
2020
Kakao Games Europe B.V
Web

Game Web Shop

Developed and maintained web services for game item sales

  • Developed and maintained backend and frontend services
  • Integrated internal Payment API
  • Integrated Payment Gateways (Adyen)
  • Integrated monitoring system and alerting system
JavaSpring BootAWSJenkinsMySQLMSSQLAdyenSentryGrafana
2020
Kakao Games Europe B.V
API

Payment API

Developed payment RESTFull API service

  • Definition and Specification of Payment API
  • Developed RESTFull API using Spring Boot, Java
  • Created API documentation
  • Integrated monitoring system and alerting system
JavaSpring BootAWSDockerJenkinsMySQLMSSQLSentryGrafana
2020
Kakao Games Europe B.V
API

Email Service API

Developed email service integration with Mailchimp

  • Definition and Specification of Email API
  • Developed RESTFull API using Spring Boot, Java
  • Integrated Mailchimp service
  • Created API documentation
  • Integrated monitoring system and alerting system
JavaSpring BootAWSJenkinsDockerMySQLMailchimpSentryGrafana
2018
Kakao Games Europe B.V
Batch

Batch Service

Developed automated scheduling service for data and report

  • Developed batch system using Java scheduler
  • Payment data processing, game item delivery, invoice generation and etc
  • Managed system monitoring and maintenance
JavaSpring BootAWSJenkinsDockerMySQLMSSQLSentryGrafana
2017
Kakao Games Europe B.V
Web

Black Desert Online Web Shop

Developed the Black Desert Online web shop page

  • Developed and maintained backend and frontend services
  • Integrated internal legacy Payment API
  • Integrated Payment Gateways (PaymentWall)
JavaSpring BootJenkinsMSSQL
2017
Kakao Games Europe B.V
Management

Payment System

Managed payment settlement, dispute, and web store product

  • Operated using third-party payment solutions called Payletter
  • Designed UI and function of payment system
  • Managed payments, reconciliation, dispute and chargeback
  • Contributed to reducing chargeback and refund rate
JiraConfluence
2016
Danal Co., Ltd.
Web

Brand Web Site Renewal

Participated in the renewal project of the brand web site

  • Developed a mobile payment history inquiry page
  • Implemented stored procedures
PythonFlaskjQueryMSSQL
2015
Danal Co., Ltd.
Web

Mobile Payment Service

Maintained mobile payment processing system

  • Maintained mobile payment service pages
  • Developed automated testing tools using Selenium
  • Managed payment processing and monitoring
PHPC#JavaScriptMSSQL
2014
Danal Co., Ltd.
Web

CRM Web Service

Developed a Customer Relationship Management web service

  • Developed web services (Full Stack)
  • Implemented stored procedures
  • Integrated VoIP using JavaScript
ASP.NETC#JavaScriptMSSQL
2014
Danal Co., Ltd.
Web

Mobile Payment Web Service

Developed a mobile payment history page for mobile screens

  • Developed web services (Full Stack)
  • Integrated payment API
  • Designed and implemented UI using jQuery Mobile
HTMLCSSjQuery
2009
Danal Co., Ltd.
Web

BilltoMobile Portal / CRM / BackOffice

Developed payment service for North America

  • Developed web services (Full Stack)
  • Implemented stored procedures
ASP.NETC#JavaScriptMSSQL