About Me
Zac Ji
Senior iOS & Indie Developer
Hi! I am Zac (Hongbo Ji). I have 10+ years of professional iOS native engineering experience, alongside cross-platform skills in Android, Flutter, and modern Web engineering.
Being fluent in Chinese, English, and Korean enables me to easily localise, design, and ship my apps (like Flux IPTV) to global markets. Currently, I am dedicated to creating streaming and utility apps within the Apple ecosystem.
Technical Skills
iOS Core
- Swift & SwiftUI
- UIKit / Auto Layout
- Structured Concurrency
- Combine & Reactive Prog
- SwiftData & SQLite Storage
Optimization
- Xcode Instruments
- Memory Leak Diagnostics
- App Launch Time Tuning
- Core Animation Frame Rates
Fullstack
- Astro / Vue / CSS Modules
- Node.js / Cloudflare Workers
- Git & GitHub Actions CI/CD
- App Store Connect Review Flow
Career & Indie Timeline
iOS Indie Development & Global Shipping
Full-time indie creator focusing on Apple ecosystem apps and AI workflows. Shipped 4 major applications:
- Lumen Noise: Clock + ambient soundscapes (iOS, macOS, tvOS, visionOS)
- LeafAid: AI-powered plant caretaker and leaf diagnostic companion
- Flux IPTV: Universal playlist player with local latency status checking
- Aibrary: Experimental app utilizing Sentry crash self-healing loops
Coupang (Seoul) · Senior iOS Engineer
Worked in the Core Platform team maintaining base frameworks for the largest e-commerce App in Korea. Led modularization and migrated legacy components to modern Swift. Operated in a fully English and Korean bilingual working environment.
ByteDance · iOS Engineer
Developed TikTok international e-commerce features. Led optimization on Lynx dynamic page framework. Improved startup metrics and page loading speeds by **over 100%** using caching, pre-rendering, and container pools. Also shipped cross-stack Flutter/Android apps and established code reviews.
ShengHuo Info Tech · iOS Engineer
Shipped "DouBai Live" streaming e-commerce iOS app from scratch. Optimized video latency and HLS streaming protocols with Tencent Cloud Live SDKs.
Kumho Software (South Korea) · Frontend Engineer
Maintained internal enterprise portals. Worked with classic Web frameworks including ASP and .NET.
Nanjing Xiaozhuang & Woosong University · Software Engineering B.S.
Majored in Software Engineering. Selected as an exchange student to Woosong University in South Korea, completing bilingual coursework in system architectures and databases.
Let's Connect
I am open for iOS/macOS custom development projects, performance optimization consulting, or general technical advising.
Get In Touch