Backend Engineer (Ruby on Rails)

What to Expect

• Work on a payment gateway and related projects shaping the platform’s future.
• Collaborate within a flat, inclusive, and largely self-organizing engineering team, having a direct influence on product and technology decisions.
• Enjoy autonomy to play to your strengths and explore areas where you want to grow.
• Drive your own career and skill development, supported by mentorship from managers and senior engineers.

International Team & Language Support

• Engineering team is highly international; English is the primary working language.
• Optional English and Japanese lessons offered to all employees to promote a diverse and inclusive culture and enable smooth team collaboration.

Role Overview

• Build and enhance systems that process payments globally.
• Main stack: Ruby on Rails (about 90% of tasks), with occasional front-end (less than 5%) and infrastructure/observability (Terraform/DataDog, less than 5%).
• Example tasks: Add new APIs in Rails; investigate, debug, and resolve payment issues; improve reliability and observability.
• Collaborate with product managers to evaluate, specify, and implement requirements.
• Participate in code reviews, refactoring, documentation, and knowledge sharing.
• Focus on code quality, testing, and best practices.

What You’ll Be Doing

• Develop robust backend systems using Ruby on Rails.
• Translate product requirements into reliable, maintainable software.
• Lead and participate in large technical projects from design through delivery.
• Write comprehensive tests to ensure high-quality software.
• Participate in code reviews and mentor teammates.

Key Requirements

• Strong experience building backend systems using Ruby on Rails in production. (Candidates with strong backgrounds in other backend frameworks are welcome.)
• Experience with scalable, high-performance web applications.
• Solid knowledge of relational databases and SQL.
• Ability to design data models and overall system architecture.
• Strong technical communication and documentation skills.
• Understanding of common web vulnerabilities and security best practices.
• Familiarity with software architecture, design patterns, and best engineering practices.

Nice to Have

• Experience with TypeScript, Vue.js, or React.
• Experience in payments or financial systems.
• Secure, reliable integration with third-party APIs.
• Understanding of database performance and data access patterns.
• Familiarity with monitoring/observability platforms such as DataDog.

Hiring Process

• 3-4 stages—initial screening, take-home exercise, technical/team interview, and a final interview with leadership.
• Focus on both technical excellence and culture fit, as well as long-term growth potential.
• Beyond the Code: How to shine in coding exercises

Perks & Benefits

• Remote-first with optional office space for in-person collaboration.
• 10 days regular vacation, plus 5 summer and 5 winter vacation days.
• Paid birthday holiday.
• Self-learning allowance and budget for skills development.
• Access to O'Reilly Learning Platform.
• Japanese/English language training.
• Twice weekly office lunch.