← Back to main page

Senior Android Developer

Salary not provided

iOSAndroid
English: Fluent

Minimum year of experience: 5

KOMOJU

Senior Android Developer (POS / Hardware Integration)

What to Expect

  • Product-focused role: Work on a cross-border payment gateway and projects that shape its future.
  • Flat and inclusive culture: Engineers participate in key product and technology decisions.
  • Self-organizing team: Take ownership over your work and contribute to areas you wish to develop.
  • Growth-driven: You drive your own growth and position by investing in new areas and skills.

International at Our Core

  • International engineering team; English is the primary working language.
  • Diversity-driven: English and Japanese language lessons offered to all employees to foster strong multicultural collaboration.

About the Position

As the first Senior Android Developer, you will:

  • Define coding standards and architectural frameworks for a new Point of Sale (POS) app using native mobile technologies.
  • Build the native mobile apps that implement a custom payment processing Platform API.
  • Integrate with hardware devices (IC card readers, NFC, magstripe, PIN pads), requiring both high-level application work and low-level systems/hardware interaction.
  • Set foundations for testing, code quality, and robust software architecture.

Ideal candidates:

  • Are experts in Kotlin & Java, producing high-performance, thread-safe, maintainable code.
  • Have proven experience handling hardware event integration, Android background services (AIDL/IPC), and complex state management on Android.
  • Bring architectural discipline—able to design testable systems and adapt quickly to new hardware documentation.
  • EMV protocol and payment transaction flows knowledge is a plus.

Responsibilities

  • Develop POS, native merchant apps, and mobile SDKs using Kotlin.
  • Collaborate with product managers and developers to define, design, and ship new features.
  • Work across tech stacks—including with backend engineers—to build out mobile functions.
  • Willingness to work with other programming languages and platform backend as needed.
  • Participate in technical and architectural reviews across both iOS and Android mobile platforms.

Who You Are

  • 5+ years professional experience.
  • Android SDK and mobile development lifecycle experience.
  • Proficient in using RESTful APIs for backend integration.
  • Strong mobile UI/UX knowledge, patterns, and best practices.
  • “T-shaped” developer: Generalist able to move across the tech stack to deliver.
  • Collaborative: Thrives in a cross-functional team environment.
  • Knowledge of cross-platform frameworks for iOS/Android is welcomed.

Nice to Have

(Not required, but please highlight in your application if applicable)

  • Experience with iOS development and architecture familiarity.
  • Prior experience working with Japanese businesses.
  • Leadership/mentorship: Lead and coach team members, foster skill development.
  • Business-level Japanese language proficiency.

What is the Process Like?

  • 3-4 stage hiring process: initial screening, take-home assignment, technical interview (incl. live coding), and final leadership interview.
  • Evaluation on both technical skills and fit for team culture, as well as long-term growth potential.

Perks & Benefits

  • Remote work embraced—office space available for those preferring onsite work.
  • Generous time-off: 10 days regular vacation, 5 days each for summer/winter, paid birthday holiday.
  • Learning budget and access to O’Reilly Learning Platform.
  • Japanese/English language training available.
  • Twice weekly office lunch.
  • Role based in Tokyo: candidates must be willing to relocate to Japan.
reco経由で応募する