Hyeonseok Jeong

Staff Android Engineer

Android engineer with 7+ years of experience building apps and SDKs. Launched and operated new services at Kakao Mobility, and redesigned the reader SDK, app architecture, and development infrastructure at NAVER WEBTOON.

Experience

Coupang Pay

Staff Android Engineer

Aug 2026 - Present

NAVER WEBTOON

Android Engineer

Oct 2021 - Aug 2026

  • Reader SDK redesign

    Led the redesign of a WebView-based ePub reader using native views and Jetpack Compose, covering SDK architecture, rendering, state management, and Android lifecycle handling.

  • CI/CD and build infrastructure

    Reduced build times by approximately 30% with a Gradle remote build cache. Built CI/CD infrastructure that allocates Kubernetes pods only during builds, reducing CI costs by at least 90%.

    NAVER D2 talk: Eliminating Android build wait times (Korean)

  • App architecture standardization

    Migrated the Series app to a multi-module architecture and standardized dependencies and build configuration with Gradle convention plugins.

  • Series app development

    Migrated UI to Jetpack Compose, launched the Banjjak Cookie in-app purchase product, and integrated Google Play Billing and rewarded ads.

Kakao Mobility

Android Engineer

Dec 2018 - Oct 2021

  • KakaoT Bike launch

    Built BLE smart-lock integration, location clustering, and rental, return, and payment flows. Integrated card payments, carrier billing, and PayPal, with idempotency keys to prevent duplicate payments and retry handling for failures.

  • Bike operations and Rentcar launch

    Led Bike operations and maintenance and Rentcar's initial development. Implemented booking, payment, and cancellation state transitions, and mentored one junior and two experienced engineers.

Samsung SDS

Cloud Platform Intern

Jun 2018 - Aug 2018

Skills

Android
  • Kotlin
  • Coroutines
  • Jetpack Compose
  • Custom View
  • WebView
Architecture
  • SDK Design
  • Multi-module
  • Clean Architecture
  • MVI
Tooling
  • Gradle
  • GitHub Actions
  • Kubernetes
  • FastAPI
  • Python

Education

Kumoh National Institute of Technology

Bachelor's degree in Computer EngineeringGPA 4.21 / 4.5

2013 - 2019
  • Presented a first-author paper at KIPS 2017 on embedded real-time lane detection, reducing computational workload by approximately 30% compared with the previous approach.