Interest
- Organization - Leadership, Culture, Performance Management, Communication
- Software Developer - Software Craftsmanship, Agile, Professionalism, DevOps, Large-scale system, Reactive system
- Private - Major League Baseball(including sabermetrics), Fitness, Fashion, Liquor
Work Experience
FingerPlus, Seoul, Korea
- Position
- Lead Engineer - 2018.02 ~ 2019.01
- Senior Engineer - 2017.04 ~ 2018.01
- Achievements
- Migrate EC2 and other component into VPC in AWS and setup VPN server/client to enhance service security
- AWS VPC, AWS EC2, Network, OpenVPN
- Design and implement Player API v1
- Replace old Player API beta to avoid exposing API key externally
- Issue page view token through server-to-server communication to use for client to request API server
- Define new player user log format and modify Player API backend to send new log stream to make log analysis deepen
- AWS API Gateway, AWS Lambda, AWS DynamoDB, Serverless Framework, JWT(Json Web Token)
- Heading to construct reactive system
- Change deployment from VM to Docker
- Design and implement Advertiser API v1
- Integrate another AD system by integrating API
- Implement Bulk Request API
- HapiJS, OAuth 2.0 (Client Credentials), JWT
- Restructuring legacy system
- Overcome slower developing speed, frequent unintended errors due to monolithic and tightly-coupled legacy system
- Motivated from optimistic concurrency, state management in the Kubernetes
- De-couple video meta, advertisement, and statisitics system respectively
- Event driven - AWS SQS
- Detect state change as compared with latest data
- De-couple system to use not SMR clip, also general-purpose video clip (In progress)
- Substitute AWS Lambda into server in Player API backend (In progress)
- Overcome the limitations with AWS Lambda - unknown error, and slow scaling speed, and hard to customize configuration
- Achieve both 1k~ TPS and ~100ms response time per 1 application in peak time
- Etc
- Define code, API, and message convention for engineers
- Introduce jira and confluence into company
- Organize monthly study sessions (OpenLab) in engineering group
- Make engineer blog using Jekyll
Opensurvey(ex. IDINCU), Seoul, Korea
- Position
- Senior Engineer - 2016.04 ~ 2017.03
- CTO - 2012.04 ~ 2016.03
- iOS Developer - 2011.07 ~ 2012.03
- Achievements
- Design new survey/response data structure and relationship between modules
- Develop functions to use external survey reference in legacy response modules
- OPENSURVEY
- From 1.0 to 2.0
- Manage OPENSURVEY accounts including registration, authentication and authority
- Spring (Spring Boot), MyBatis, JPA, HTML/CSS, LESS, Javascript, jQuery, Redis, Spring Security, Spring Session
- Common Questionnaire Modules
- Improve performance function to store responses asynchronously using RabbitMQ
- Implement Question Group Rotation feature and External Questionnaire Reference feature and so on
- Re-design front/backend module
- Spring, Struts2, MyBatis, Javascript, jQuery, RabbitMQ, Node.js, React, Kafka
- OVEY
- Develop and maintain OVEY 1.0 iOS Application
- Develop single sign on system related with OPENSURVEY and OVEY
- Develop shop and account managing system in OVEY
- Spring (Spring Boot), MyBatis, HTML/CSS, LESS, Javascript, jQuery
- Re-construct legacy system (From monolithic to MSA)
- Adapt REST API
- Introduce Apache Kafka for messaging system
- Introduce Netflix Eureka for service registry/discovery system
- Etc
- Introduce gerrit, jira and confluence into engineering team
- Establish code conventions including Java, Javascript, html/css
- Introduce ployglot (Java, Javascript, Python)
Memory Division, Samsung Electronics, Hwasung, Korea
- Position
- Associate Software Engineer - 2010.03 ~ 2011.07
- Software Engineer - 2008.02 ~ 2009.02
- Achievements
- Develop and maintain NAND Flash Firmware (FTL, Flash Translation Layer) - applied to embedded storage, especially, OneNAND and Flex-OneNAND
- STL (Sector Translation Layer) from 1.1 to 1.2
- Improve wear-leveling algortithm (10% improvement) - count/store wearing(erase) count per block and calculate a minimum erase count block to use next block to use
- Maintain BML(Block Management Layer) and LLD (Low-Level Device layer)
- Develop UFD(USB Flash memory Drive) UA1
- Study existing FTL technologies
- Design architectures for next generation storage device
Education
Master’s degree, Computer Science and Engineering, Seoul National University (2006 - 2008)
- Mobile Embedded System Lab.
- GPA 4.15
- Achievements
- Implement NAND flash driver and block device driver
- Implement the static analyzer of C– (Subset of C) and that of Effective Inference
- Research towards obtaining IPRs for mobile applications (with Pantech)
- Patent - 통합 IP 메시지 시스템의 일대다 파일전송 방법(Method for Transmitting a File or More from One Device to Many under the Converged IP Messaging System)
- 지상파 DTV 방송프로그램 보호 기술 개발 (with ETRI, 한국전자통신연구원)
- Research media sharing and multi-device support protocol within CPM system (with Samsung Electronics)
- Research for next generation flash memory storage (with Archi Lab. in SNU, Samsung Electronics, Hanyang University, M-tron, and so on)
- Publication
- Enhancement of CPM (Converged IP Messaging) System - 2008.02
- Awards
- Samsung Electronics Scholarship, Samsung Electronics - 2007.03
Bachelor’s degree, Computer Science and Engineering, Seoul National University (2002 - 2006)
- GPA 3.71
- Publication
- Implementation of GTP(Game Transport Procotol) - 2006.02
- Awards
- Graduation with Honors (Cum Laude), Seoul National University - 2006.02
Skills & Expertise
- Programming Languages
- Java
- Javascript
- C/C++
- Groovy (Elementary)
- Python (Elementary)
- Objective-C
- nML
- Deployment
- Docker
- AWS ECS
- Kubernetes (in Study)
- Framework / Library
- Java
- Spring Framework - Spring Boot, Spring Security, Spring Session, Spring Cloud
- Test Framework - JUnit, Spock, and so on
- JS (Javascript)
- Front
- jQuery
- React (Elementary)
- NodeJS
- Test framework - mocha, chai, jest, and so on
- Markup - HTML/CSS/LESS/SCSS
- Databases
- Embedded System
Languages
- Korean (Native)
- English (Intermediate)
Publications
Translation
