Coupang Review Team

Achieved GMV +1.04%, review submission rate +152% through 24 service experiments. 20x message consumption speed through Kafka optimization.


Coupang Review Team

Coupang | Backend Engineer

2020.01 ~ 2022.05

Key Achievements

  • Business Metrics Improvement: Participated in 24 service improvement experiments (A/B Tests) over 2 years, achieving โ€˜Total GMV per customer +1.04%โ€™ (2020Q1), โ€˜Review submission rate +152%โ€™ (2021Q2)
  • Large-scale System Optimization: Improved Kafka consumer architecture in review domain, achieving 20x increase in message consumption speed, CPU usage reduction from 80% โ†’ 20% at peak, successfully processed 7 million Lag caused by incidents
  • Security/Privacy Enhancement: Completed zero-downtime migration of PII anonymization/separation/deletion system across 145 tables, 581 APIs, 83 Batch Jobs, 29 Kafka Consumers without incidents

Security (Privacy Protection & Enhancement) Work

  • Conducted privacy protection work to anonymize dormant/withdrawn member information and segregate or completely remove related data in review domain
  • Surveyed all 145 tables and selected 72 tables requiring data separation
  • Developed functionality to extract table features from ORM by analyzing Spring Data JPA, storing dormant member data in JSON format for separate storage
  • Led 3 junior developers to apply Vault to 19 roles & OAuth2 to 7 roles

Review Domain Improvement & Performance Optimization

  • Legacy Kafka Consumer Performance Optimization: Split one massive logic into 7 tasks, improved to distributed processing with 2 internal topics and 7 consumers
  • Redis (Lettuce) Migration: Unified multiple cache infrastructures (Local Cache, Memcached, Elasticache Redis) used by review system
  • API Latency Improvement: Achieved average 30% improvement through multi-threaded API calls, cache application, duplicate logic removal