Frontend Engineer(React Native)

TLDR

Develop user-facing Android and web frontend applications for warehouse systems, ensuring optimal performance in demanding production environments while collaborating across teams.

Mujin creates MujinOS, the intelligent operating system for industrial robotics. By leveraging real-time digital twins, MujinOS seamlessly connects and orchestrates equipment to achieve fully autonomous operations. At our core is  Machine Intelligence (MujinMI), a unique approach offering advanced perception, planning, and control algorithms that solve the most challenging automation problems. Trusted by globally recognized companies, we are redefining supply chain efficiency. Headquartered in Japan with growing teams in China, the US, and Europe, we invite you to join a dynamic environment where you can shape the future of automation. Team Introduction As a Software Engineer on Mujin’s Warehouse Execution System (WES) & Fleet Management (FM) team, you will focus on developing user-facing Android and web frontend applications used daily in warehouse operations. Your work directly shapes how operators interact with warehouse systems through industrial Android devices and browser-based interfaces. The team specializes in building reliable, high-quality frontends that run in demanding production environments, where stability, performance, and usability are critical. You will work closely with backend engineers, product managers, designers, and operations teams to deliver intuitive, responsive, and maintainable interfaces that support long-running workflows and mission-critical operations at scale. Responsibilities React Native - Build and ship React Native features for Android - Implement UI from designs and product requirements - Integrate with backend APIs (REST/GraphQL), auth, and analytics - Debug and fix issues across devices/OS versions; improve stability - Optimize performance and app responsiveness - Write tests and support CI/CD and release processes - Participate in code reviews and maintain code quality through refactoring - Collaborate with product, design, and backend teams to deliver end-to-end features Android - Design, develop, and maintain Android applications for industry devices used in warehouse environments. - Implement features that interface directly with device hardware layers, including barcode scanners, cameras, physical buttons, NFC/RFID, printers, Bluetooth, and other peripherals. - Work with vendor-specific SDKs. - Debug and resolve issues across application, OS, and device layers. - Build applications optimized for offline usage, long-running sessions, and high reliability. Web Frontend - Develop web frontend applications using React and TypeScript. - Ensure applications are responsive, accessible, and work across browsers and devices. - Optimize frontend performance through profiling, bundle size reduction, and effective use of browser APIs. Collaboration & Quality - Collaborate with Product Managers, Designers, backend engineers, and operations teams. - Participate in code reviews, knowledge sharing, and mentoring. - Triage, debug, and resolve production issues across Android and web systems. - Contribute to CI/CD pipelines, testing, and code quality improvements. Tech Stack Android - Kotlin, React Native - Android SDK, Android Jetpack - AOSP-based devices, OEM SDKs Web Frontend - TypeScript, React Tooling & Build - Rsbuild - Vitest - ESLint Backend & Infrastructure - Python - RESTful APIs - GraphQL - Docker Collaboration - Figma - Confluence - GitLab Minimum Requirements
  • 3+ years of professional software development experience.
  • Strong knowledge of JavaScript, TypeScript, React (Preferrably React Native), and CSS.
  • Experience integrating applications with device hardware features or SDKs.
  • Experience with testing frameworks and CI/CD pipelines.
  • Solid understanding of software engineering fundamentals and performance optimization.
  • Preferable Requirements
  • Experience developing Android applications using Kotlin.
  • Experience developing applications for industrial devices.
  • Proven experience maintaining shared frontend libraries or component systems.
  • Experience with frontend performance monitoring and optimization.
  • Familiarity with PixiJS, rich animations, or interactive UIs.
  • Experience with offline-first design and data synchronization.
  • Experience with Figma plugin development.
  • Experience with i18n and localization workflows.
  • Attractiveness
  • We are looking for those who are prepared to dedicate themselves to facing big challenges, work proactively and independently, and take ownership when working with members across the teams!
  • You will get your “hands dirty” working on all aspects of the industrial robot controller, not being confined to a specific component in the system. The work is challenging, mostly like something that you have never done before, requiring extensive research.
  • Balanced, Modern Client-Side Tech Stack
  •  Android (core focus): Kotlin, device integration, reliability engineering
     Web Frontend: React + TypeScript for operational and management interfaces
    Interview Process:
  • Coding Assessment: Initial technical evaluation.
  • HR Interview: Discussion with Human Resources.
  • Technical Interview: One or two rounds with the frontend team's manager.
  • Final Interview: Cultural fit interview with hiring manager.
  • Location
    3-8-5 Tatsumi, Koto-Ku, Tokyo 135-0053, Japan
    Work Hours
    8:45 - 17:45 (with a 60-minute break)
    Salary
    ・Based on experience and skills
    ・Salary revision twice a year
    ・Additional bonuses available based on performance
    Holidays
    ・Every Saturday and Sunday
    ・Annual paid leaves
    ・Maternity leave and Childcare leave
    ・Other holidays as defined by the company
    Company Benefits
    ・Flexible dress code policy
    ・Commuting allowance
    ・Japanese Social Security (Health Insurance, Pension, Labor Insurance)
    ・Monthly team dinner support
    Japan Relocation Support
    ・Visa sponsorship
    ・Flight ticket support
    ・Shipping expenses coverage up to a specified limit
    ・Assistance for housing

    Benefits

    Flexible Work Hours

    Flexible dress code policy

    Free Meals & Snacks

    Free buffet lunch every workday

    Health Insurance

    Japanese Social Security (Health Insurance, Pension, Labor Insurance)

    Other Benefit

    Exclusive Employee Gym Access

    Visa Sponsorship

    Mujin develops MujinOS, an intelligent operating system for industrial robotics, focusing on advanced automation solutions that enhance supply chain efficiency. By leveraging unique robotic control technology, we tackle pressing societal challenges like labor shortages and logistics issues, making industries smarter and more efficient.

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