Yuta Ooka

Led solo development of an iOS application prototype, building the entire UI layer and integrating advanced APIs for secure content access and immersive UI.

• Led a two-month solo effort to deliver the first iOS application prototype, building the entire UI layer using SwiftUI and SwiftData.
• Integrated swift-openapi-generator to auto-generate type-safe APIs, reducing boilerplate and enhancing development efficiency.
• Implemented EPUB ingestion with AES-GCM encryption/decryption via CryptoKit, ensuring secure offline access to licensed content.
• Adopted new APIs introduced in iOS 26, updating TabView and NavigationStack to align with platform changes and integrating Liquid Glass effects for a modern, immersive UI.

Developed a fundraising prototype and led the creation of an iOS avatar-streaming app, securing significant pre-seed capital and resolving critical technical dependencies.

• Built a fundraising prototype that secured ¥30 Million (approximately $190K) in pre-seed capital for Sabab within three months.
• Led development of an iOS avatar-streaming app utilizing SwiftUI and Live2D Cubism SDK.
• Diagnosed and fixed build errors in AWS C HTTP, IO, and SDKUtils libraries, submitting patches upstream to enable clean builds for Swift developers.

Led key initiatives for the LINE messenger app, enhancing performance, reliability, and user experience for over 200 million monthly active users across Asia-Pacific.

• Re-wrote the iCloud backup module with Swift Concurrency, cutting backup-error rates by over 71% and increasing test coverage to 85% for improved reliability.
• Led a team of four iOS engineers in redesigning the Chats list, shipping internal beta on schedule and gathering feedback from 300+ employees in the first week.
• Mentored a newly onboarded senior iOS engineer, enabling on-schedule delivery of key components for the Chats-list redesign through pair-programming and targeted code reviews.
• Boosted Chats-list scroll performance by 37% by migrating to UICollectionView Diffable Data Source with ID-only snapshots and enabling on-demand Core Data faulting.
• Drove quality through weekly code reviews (averaging 15 PRs/week), preventing regression bugs, and mentored two junior engineers on test-driven development.
• Led the secure key management system for the Premium Backup project, utilizing Keychain to store E2EE and master keys for end-to-end encrypted backup and restore.