KOMOJU is the leading cross-border payment gateway for Japan. We power payments for companies like video game distribution platform Steam and the popular mobile app TikTok. Today we help thousands of merchants by providing them with the payment infrastructure they need through developer-friendly API’s to integrations on popular platforms like Shopify and Wix; we help our merchants grow in all markets they are expanding.
We are product focused, meaning you will work on our payment gateway and any other projects towards building the future of KOMOJU. You will work with other engineers in a flat and inclusive culture where engineers have a say in both key product and technology decisions. The culture is largely self-organizing, which means engineers have both a stake and ownership in what they work on. Engineers play to their strengths, but are also able to invest in areas where they want to grow within the team. At KOMOJU, you are the main driver behind your growth and position in the company.
Most of our engineering team members come from outside Japan. English is the primary language used, and throughout the company, many people are at least bilingual.
Being an international company we know the importance of bilingualism. We offer all employees a choice between optional English and Japanese lessons to help create a culture of diversity and ensure smooth collaboration across teams.
We are looking for our first Senior Android Developer to help build KOMOJU’s Point of Sale (POS) application and native mobile apps, which implements our Platform API for payment processing. As our first Android engineer, you will play a key role in defining coding standards, architectural decisions, and the frameworks we adopt.
Our ideal candidate has strong experience building mobile applications and is eager to expand across languages and frameworks to deliver exceptional mobile experiences. Testing and code quality are central to our engineering culture, so a solid understanding of testing principles and methodologies is essential.
We are not just looking for a standard mobile developer, but for a Systems-on-Android Engineer. You should have expert-level proficiency in Kotlin and Java, with the ability to write high-performance, thread-safe, and maintainable code.
This position sits at the intersection of application logic and hardware integration. You will be responsible for integrating SDKs that control IC card readers, NFC modules, magstripe readers, and PIN pads. Success in this role requires experience with low-level hardware event handling, Android background service communication (AIDL/IPC), and complex state machine management.
Knowledge of the EMV protocol and payment transaction flows is a plus. However, as EMV processing is specialized, we prioritize engineers with strong architectural discipline who can design robust, testable systems and quickly master hardware documentation.
Requirements
These aren't required, but be sure to mention them in your application if you have them.
We aim to keep our hiring process thoughtful and efficient, typically involving 3-4 stages depending on the role: an initial screening, a take-home assignment, a technical (team) interview with live coding exercise, and a final interview with leadership. Throughout the process, the team evaluates candidates not only on technical skills but also on their alignment with team culture and potential for long-term growth.
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Benefits
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