Job DescriptionTranslated from Japanese
Web Application Engineer (IR Domain LLM New Product)
▼Job Description
Background
We are currently driving the development of a new product utilizing LLM within the IR (Investor Relations) departments of corporations.
This service had a closed release in July 2025. We are already seeing a steady increase in customers, and it is expected to become a new pillar of our business.
We are looking for a full-stack engineer who can lead the product's growth phase, seamlessly integrating business and technical strategies, and take full responsibility for the product's design, development, and operation.
We are seeking a strong leader who can leverage cutting-edge generative AI technology to solve fundamental customer challenges and drive business growth.
Job Overview
Towards the realization of our mission, "Let's create a good economy," we are developing a product that streamlines and enhances operations in the IR department. As a full-stack engineer in the new business team, you will be responsible for product design, development, and operation.
This initiative is driven by a lean and agile team consisting of a Development Lead, 2 Engineers, 1 Product Manager (PdM), and 1 Designer. You will engage in product development from an engineering perspective, considering business strategy to maximize customer value in the mid-to-long term.
Your specific mission will be to collaborate with the PdM to handle everything from discovery to delivery, leading architectural design with future scalability and maintainability in mind, improving development processes, and maximizing business outcomes through the product.
Responsibilities
Lead Architecture Design and Technology Selection
Design and make technical decisions for an architecture that supports future scalability and continuous product growth.
Design and Implement Core Features Utilizing LLM
Design and implement prompt and context engineering utilizing multimodal data for the core of the product.
Continuous Feature Development with Go (Backend) x Next.js (Frontend)
Take Ownership of the Entire Development Process
Lead efforts to improve the productivity and accelerate the output speed of the entire development team.
Discovery with PdM (Requirements Gathering, Specification Discussion, Definition)
Deeply understand business strategy and requirements, and work closely with the PdM to explore "What are the fundamental customer challenges?"
Ensure and Improve Technical Quality
Promote code reviews, performance optimization, and resolution of technical debt.
▼Required Skills/Experience
Experience leading technical decision-making and promotion that impacts organizations larger than your team.
Experience considering technical strategy from management and business strategy.
Experience in improving team processes, enablement, and various automation efforts to enhance team productivity.
5+ years of experience in web application design and implementation.
Development experience using strongly-typed languages such as Java, Go, or TypeScript.
Proficiency or strong interest in technologies for creating high-quality products, such as TDD and DDD.
Technical leadership and code review experience in small teams.
▼Preferred Skills/Experience
Experience involved in launching and growing new businesses from inception to scale.
Experience with Proof of Concept (PoC) for products incorporating LLM / Generative AI.
Experience designing and implementing integrations with external SaaS APIs such as Salesforce.
▼Ideal Candidate Profile
Execution-first individual who pursues fundamental customer value and can rapidly iterate on hypotheses.
Leadership capable of guiding the development team from requirements definition to release.
Individual who actively keeps up with the latest generative AI technologies and can translate them into product value.
Individual willing to commit to business growth beyond direct development, such as through recruitment, technical outreach, or customer interviews.
▼Job Highlights
Autonomy as a Full-time Engineer in a Lean Team
Experience a wide range of technical decision-making related to product development, including technology selection, architecture design, development process construction, and mid-to-long-term organizational structure development.
Growth Experience in the 0 to 1 Phase
Practical experience in rapidly iterating on hypotheses with the PdM for a product immediately after MVP release, aiming for Product-Market Fit (PMF) achievement.
Technical Experience in LLM Practical Application
Practical experience in applying LLM to a real product, delivering valuable output to users by leveraging data in IR operations.
▼Development Environment
Server-side
Go
Frontend
React / Next.js / TypeScript
Infrastructure
AWS / Terraform / Fargate / ECR
Database
Aurora PostgreSQL
Testing Tools
Datadog Synthetics / Playwright
Tools & Services Used
Slack / Gather / Figma / Findy team＋ / Notion / Miro / diagrams.net / Cursor
▼Employment Type
Full-time (No fixed term)
▼Probationary Period
3 months (up to 6 months)
▼Salary
Annual salary: ¥7,000,000 - ¥20,000,000
▼Annual Salary Lower Limit (10,000 JPY)
700
▼Annual Salary Upper Limit (10,000 JPY)
2000
▼Work Location
Kokusai Kogyo Mita 2nd Building 9F, 3-11-24 Mita, Minato-ku, Tokyo 108-0073 (Remote work is also possible)
▼Working Hours
10:00 - 19:00
▼Break Time
1 hour
▼Overtime Work
Available
▼Holidays, Paid Leave, Special Leave
Complete two-day weekend system
- Saturdays, Sundays, National Holidays, Year-end holidays (December 28 - January 3)
Leave
- Annual paid leave (10 days granted upon joining), congratulatory/condolence leave, childcare leave, family care leave, menstrual leave, etc.
▼Benefits
- Rental housing system
- Subsidy for PC peripherals
- Corporate Defined Contribution pension plan, etc.
▼Insurance Enrollment
Health Insurance, Employees' Pension Insurance, Employment Insurance, Workers' Accident Compensation Insurance
▼Measures to Prevent Passive Smoking at the Workplace
No smoking within the premises (smoking area available outdoors)