Senior iOS Engineer

Employment: Full Time

Location: Tokyo (Hybrid)

Salary: Up to ¥22,000,000

【About the Role】

Our Client, a leading Japanese tech company whose consumer mobile app is used by millions of users, is looking for a Senior Software Engineer (iOS) to join its Mobile Enablement team. The team's mission is to turn mobile development into a seamless, automated, cross-platform ecosystem, while also building features with real business impact.

【Responsibilities】

• Design, build and maintain high-quality iOS features in Swift, including AI-driven functionality
• Own feature development end-to-end, from requirements and design through implementation and release
• Lead architectural design for complex app components and systems
• Optimize app performance, stability and responsiveness across devices
• Work closely with Machine Learning, Backend and Infrastructure teams to deliver seamless mobile experiences
• Contribute to the evolution of the mobile platform, build systems and development workflows
• Drive code quality through code reviews, testing and best practices
• Mentor junior engineers and lead cross-functional technical initiatives

【Requirements】

• Bachelor's degree in Computer Science or equivalent practical experience
• Strong proficiency in Swift and iOS frameworks (UIKit, SwiftUI, Combine)
• Solid understanding of mobile architecture patterns
• Experience developing and maintaining large-scale iOS applications
• Experience integrating with backend APIs
• Strong analytical and problem-solving skills
• Excellent communication skills and a passion for mobile products
• Business-level English

【Nice to Have】

• Experience with apps with large scale traffic
• Expertise in app performance optimization
• Deep experience with SwiftUI and Swift Concurrency (async/await)
• Familiarity with CI/CD, automated testing and build tooling (e.g. Bazel, fastlane, GitHub Actions)
• Experience using AI coding tools (e.g. Claude Code, Cursor, Codex) in daily development
• Experience leading technical initiatives across teams
• Open-source contributions
• Strong sensitivity to UI/UX
• Japanese language proficiency

【What We Offer】

• Annual salary of up to ¥22,000,000
• Hybrid work with full flextime (no core hours)
• A modern tech stack: Swift, SwiftUI, Swift Concurrency, Swift Testing, Bazel, fastlane, Protocol Buffers, GitHub Actions
• Opportunity to build AI-driven features for a product used by millions
• A global, English-speaking engineering environment in central Tokyo