Job title: Full-stack Engineer(English Only)RT
Job type: Permanent
Emp type: Full-time
Industry: IT & Telecommunications / IT・通信
Functional Expertise: Technical (IT) / 技術職(IT)
Salary: Negotiable
Job published: 2026-03-10
Job ID: 70135

Job Description

Lead the Evolution of Generative AI. Join an Elite Team Developing Next-Generation SaaS Solutions!

 

 

■ Job Title

Full-stack Engineer (Leader or Member)

 

 

■ Company Overview

We are a cutting-edge AI startup focused on developing innovative SaaS applications utilizing Generative AI. Our development organization consists of approximately 65 members divided into specialized groups for Client Solutions, In-house AI SaaS, and Common Infrastructure (Infra/Data/AI R&D). We pride ourselves on a "small but elite" team environment where engineers have the creative freedom to design products that deliver user-friendly solutions and solve complex technical challenges.

 

■ Your Role and Responsibilities 

• Design and develop SaaS products leveraging Large Language Models (LLM).
• Lead projects to integrate multiple APIs and create new API structures.
• Design and build highly efficient, reusable, and maintainable systems.
• Develop frontend applications using TypeScript and Next.js.
• Implement server-side logic using Python or Java with a focus on performance.

 

■ Experience and Qualifications

• Bachelor's or Master's degree in Computer Science, Software Engineering, AI, or related fields.
• 3+ years of experience in web application development using modern frameworks.
• 2+ years of experience in server-side implementation.
• Proficiency in at least one backend language (e.g., Python, Java).
• Experience with cloud services (GCP/AWS/Azure) and container technologies (Docker, Kubernetes).
• Fluency in English and/or Japanese (business level or higher).

 

■ Additional Preferred Qualifications

• Experience in developing SaaS web applications and large-scale, complex architectures.
• Basic understanding of and strong interest in Generative AI.
• Proactive in staying updated on technology trends and sharing knowledge.

■ Good Reasons to Join

• Cutting-Edge Exposure:Work directly with the latest LLM technologies and Generative AI tools.
• Learning Support: Full coverage for AI tools (ChatGPT, Claude, etc.), technical books (30k JPY/half-year), and language learning.
• Well-being & Flexibility: Includes a monthly "Refresh Allowance" (5k JPY), housing allowance for designated areas, and hybrid work (3 days office / 2 days remote).
• Growth & Impact: High-growth startup environment with stock options available and reviews twice a year.

 

■ Work Location

Tokyo

 

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