Jae Young Choi

Built key customer-facing iOS features that improved user experience for 50k+ DAUs while maintaining a 4.8-star App Store rating with 11k+ reviews. Led refactoring of the iOS camera feature and documented proof-of-concept, technical review, and risk mitigation to guide safe delivery. Organized project planning with product and design, parallelizing execution across three engineers to ship the feature on schedule. Developed iOS regionalization efforts, including a heavy network refactor to support JWT, helping expand into the EU and grow ARR from $20M to $50M over the following years. Improved sync times by 80% through Xcode profiling (Time Profiler), triaging hangs, and optimizing disk reads/writes via multithreading. Collaborated cross-team with product, design, QA, Android, and backend; performed peer reviews to uphold code quality and architectural standards; and debugged critical customer issues via on-call rotations to maintain 99.75% crash-free sessions.

Refactored an Objective-C codebase to Swift 4 and built an MVP as the sole iOS engineer. Integrated third-party services including OAuth and Google Firebase for authentication and data functionality. Designed and implemented an asynchronous networking layer to load and cache product images efficiently. Built and shipped a beta-testable iOS application from scratch in under 9 months, despite limited prior mobile development experience.