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
Requirements
- 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
While not specifically required, tell us if you have any of the following.
- 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.
