Job description
About KOMOJU
KOMOJU (by Degica) 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.
What to expect
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.
International at our core
Around half of our team members come from outside Japan. English is the primary language used within our engineering team, and throughout the company, many people are 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.
About the position
We’re a small, high-trust team where individual ownership is valued and decision-making is collaborative but lightweight. This role is not part of an SRE team, and it’s not deeply product-facing. Instead, you’ll focus on building and maintaining core backend systems and internal tools that empower our product engineering teams to move faster and more safely.
The work is a mix of greenfield development and infrastructure stewardship. You might be spinning up a new internal service one week and helping a product team debug a scaling issue the next. We value clean abstractions, minimal operational overhead, and pragmatic solutions.
This role spans a wide range of technical areas—from backend development in Rust and Rails, to occasional frontend work, to infrastructure and observability. We don’t expect expertise in everything from day one, but you should be comfortable learning new tools, systems, and domain knowledge as needed.
Responsibilities
Design, build and maintain systems and internal tools using Rust and Ruby on Rails
Develop and support components used across the organization, such as CI pipelines, observability tooling, and shared libraries
Take ownership of under-maintained or legacy components, bringing clarity, stability, and improvement to critical but overlooked parts of the system, including occasional frontend or cloud infrastructure work
Provide thoughtful feedback through code reviews and architecture discussions
Identify and prioritize high-leverage opportunities that improve team velocity, system clarity, security, performance, and long-term maintainability
Champion quality and reliability through automated testing, proactive monitoring, and iterative improvement of production systems
Production experience with Rust
Strong communication skills—able to clearly document technical decisions and collaborate effectively across teams, including product engineering and SRE
Strong grasp of software architecture, design patterns, and maintainability best practices
Practical experience with observability practices, including structured logging, metrics, and distributed tracing
Solid understanding of database performance characteristics, including indexing, query patterns, and caching strategies
Familiarity with common web security risks and mitigation strategies (e.g., injection, CSRF, access control)
Nice to Haves
*These aren’t required, but be sure to mention them in your application if you have them.*
- Experience with any of: Ruby/Rails, JavaScript or TypeScript, Vue.js, React, Terraform, AWS, or observability tools like Datadog and OpenTelemetry
- Familiarity with payment systems, payment flows, or financial infrastructure
- Japanese language ability (reading or conversation)
*We’re hiring for multiple openings across different seniority levels. The final title and scope of responsibilities will be determined based on your experience and performance throughout the interview process.
- At Degica, we embrace remote work while also offering office space for those who prefer in-person collaboration
- 10 days regular vacation, additional 5 days summer and 5 days winter vacation
- Paid birthday holiday
- Budget for self-learning allowance, to ensure our employees’ skills remain current
- Language training for Japanese
