Senior IOS Engineer

Job Description

Appealing Points:

• Opportunity to work on RF tuning and optimization for cutting-edge 4G/5G, IoT, and NTN networks, building deep expertise in next-generation wireless technologies
• Hands-on exposure to KPI analysis, parameter optimization, SON tuning, and network troubleshooting for strong technical growth in radio performance engineering
• Dynamic role collaborating with global clients and teams, offering excellent opportunities to develop ownership, problem-solving, and technical leadership skills

Annual salary : 5 Million yen and above

Job Responsibilities:

• Architect and build modular, maintainable iOS apps using Swift, modern patterns (MVVM, Clean Architecture, VIPER, Coordinator) and SwiftUI/Combine or RxSwift..
• Collaborate on backend API design (REST) , data schemas and authentication flows to meet mobile requirements.
• Lead the design of scalable, event-driven microservices and data pipelines that power your client-side features.
• Own app performance: use Xcode Instruments (Time Profiler, Allocations, Leaks, Network), os_signpost, Instruments Automation and custom logging to diagnose and resolve CPU, memory, storage and networking bottlenecks.
• Establish and enforce code quality standards, automated linting (SwiftLint), static analysis and security scanning (SonarQube, Danger, SecureHeaders).
• Build and maintain CI/CD pipelines (GitHub Actions) for automated builds, unit/UI tests and phased rollouts via TestFlight.
• Mentor mid-level engineers on best practices for TDD, observability (Crashlytics, Firebase Analytics) and architectural reviews.
• Troubleshoot complex production issues, conduct root-cause analysis and implement long-term fixes and performance monitoring dashboards.
• Contribute to technical documentation, API specs, design reviews and architectural roadmaps.

Job Qualifications:

• Bachelor’s degree in computer science or related technical discipline
• 7+ years of professional iOS development experience in Swift/Objective-C.
• Deep understanding of iOS frameworks, app lifecycle, memory management (ARC), threading (GCD, OperationQueue) and background execution (URLSession, BGTask).
• Proven track record building large-scale apps (100K+ DAU) with high stability and responsiveness.
• Expertise in debugging and profiling tools: Xcode Instruments (Time Profiler, Allocations, Leaks, Network), Crash Reports, LLDB.
• Strong background in RESTful API integration, offline persistence (Core Data, Realm, SQLite).
• Solid grasp of modern architecture patterns (MVVM, VIPER, Clean Architecture), dependency injection (Swinject, Resolver) and modular codebases.
• Comfortable working in an Agile environment
• Hands-on with building CI/CD, containerization (Docker).
• Excellent communication skills, ability to drive technical decisions and simplify complex problems for cross-functional teams.

Preferred Qualifications:

• Prior experience as a technical lead or architect in an Agile/Scrum environment.
• Familiarity with SwiftUI, Combine, async/await and Apple’s modern concurrency model.
• Exposure to cross-platform frameworks (Flutter, React Native) or Kotlin Multiplatform Mobile.
• Knowledge of mobile security best practices (Keychain, biometrics, SSL-pinning, encryption).
• Experience with A/B testing and feature-flagging platforms (Firebase Remote Config, LaunchDarkly).
• Open-source contributions to iOS libraries or public speaking/blogging on iOS topics.

Languages Required: Elementary level Japanese and business level English

Company Description:

We are a strategic digital transformation company helping businesses evolve through cloud-native technologies.

As a leading AWS Advanced Consulting Partner with 18 years of deep expertise, commitment to digital innovation, service excellence, and customer success, we understand what it takes to make our clients’ cloud migration and modernization business goals a reality with the most advanced technologies and services the cloud has to offer.

Working strategically, we enable enterprises to unlock new business capabilities, rapidly scale, and accelerate growth on the cloud. To further eliminate the repetitive, time-consuming, and labor-intensive work for every cloud-native solution, we leverage our accelerator, ARC - a true differentiator in the industry.