Software Engineer - Backend

This role sits at the intersection of core platform engineering and new business development within a global leader in AI-powered domain expertise services. You will be responsible for building and scaling backend systems that extract and accumulate useful knowledge from diverse data sources, as well as developing high-quality software for new, high-impact business initiatives from the 0→1 phase.

Key Responsibilities

• Platform & Feature Development: Formulate development plans, design, implement, test, and operate web applications and backend APIs for both internal knowledge extraction platforms and new customer-facing products.
• Modeling & Architecture: Perform domain and data modeling focused on future scalability and product evolution. Design architectures that balance high quality with high development productivity.
• Engineering Productivity: Build systems to enhance developer experience, including schema-driven development, library creation, CI/CD pipelines, and automated testing.
• Continuous Improvement: Lead various automation efforts, establish operational processes, and maintain technical documentation to improve team productivity and product quality.
• Innovation & Technical Selection: Take responsibility for technology selection and the stable delivery of high-quality software, balancing business growth with technical investment and debt management.
• Leadership & Mentoring: Provide guidance, mentoring, and coaching to team members as needed to foster a high-performing engineering culture.

Requirements

Must-Have Skills

• Experience: 5+ years of professional experience in web system development and maintenance.
• Programming: Practical development experience with at least one (preferably multiple) major languages such as Python, Java, Go, or Rust.
• Cloud & Infrastructure: Hands-on experience designing and building systems using AWS, GCP, or Azure.
• Containerization: Practical experience with Docker and other container technologies.
• Database Management: Experience in development and operation using Relational Databases (RDB).
• Code Quality: Proven experience in initiatives to improve code quality and team productivity, including technical selection and implementation.
• Language: Business-level Japanese proficiency (Equivalent to JLPT N2 and above); interviews will be conducted in Japanese.

Preferred Experiences

• Architectural Patterns: Practical experience with DDD (Domain-Driven Design) or Clean Architecture.
• Modern Infrastructure: Experience with Kubernetes, Terraform (IaC), and Microservices architecture.
• Technical Depth: Knowledge of I/O and algorithm optimization, performance tuning, and web security best practices.
• Specialized Engineering: Experience with Natural Language Processing (NLP), parsing, data structures, and data visualization.
• Frontend Exposure: Experience with modern frontend frameworks such as React, Vue, or Angular.
• Global Collaboration: High communication skills to collaborate with diverse team members across different cultural backgrounds (fluency in both English and Japanese is a significant plus).

Benefits

Work Environment

• Schedule: Full flextime system (no core time) or a discretionary work system.
• Location: Tokyo (specific area hidden); full remote work is generally not available, though flexible arrangements may be discussed for new projects.
• Holidays: 120+ days off per year, including a complete five-day work week (Sat/Sun off) and public holidays.
• Vacations: Paid leave (granted upon joining), New Year’s holidays, and special leaves (sick leave, birthday leave, work-life balance leave, and parental leave).

Compensation & Perks

• Salary Range: Determined by experience and skills
• AI Tools: Full distribution of advanced AI tools to all employees (e.g., ChatGPT Enterprise, Gemini for Google Workspace, etc.).
• Developer Support: Access to cutting-edge development assistance tools (e.g., Cursor, GitHub Copilot, Devin, etc.).
• Growth Support: Dedicated budget for self-improvement and language learning assistance.
• Social & Health: Complete social insurance, influenza vaccination assistance, and employee stock ownership programs.
• Side Jobs: Allowed with prior permission.