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 01 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 Years 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.