★Founding Full Stack Engineer (Sales AI Agent） | AI+Marketing
- Japanese: Business Level Required
◆ Famous Venture Company
◆ Flextime & Fully Remote Work
◆ In-house Products/Services
◆ Global Team
◆ Annual salary: 7 million yen - 11 million yen
-------------【About the company】-------------
The company provides a communication platform that leverages LINE to bridge the gap between businesses and their customers. They offer specialized solutions across a broad range of industries, including human resources, education, and real estate.
By placing their proprietary product at the core of their strategy, the company helps clients optimize communication to drive revenue growth and reduce operational costs. Currently, they are heavily focused on accelerating feature development and further enhancing their support ecosystem.
-------------【 Job Description】-------------
This product is an AI-native customer engagement platform designed to optimize interactions between enterprise clients and their customers. Deployed at major financial institutions from Day 1, it is already utilized by tens of thousands of employees as a daily operational platform.
The company is seeking a Founding Full-Stack Engineer / Tech Lead to drive and establish a brand-new domain within the product from scratch. In this role, the engineer will lead the architecture design and technology selection for an AI agent platform that supports pre- and post-sales activities. While leveraging the main platform's core authentication infrastructure, the engineer will develop an independent product lane accessible from the global navigation menu with high autonomy.
Because components will be built entirely from the ground up, this position offers a unique opportunity to establish a next-generation development workflow that fully leverages LLMs such as Claude. As an initial team member, the engineer will play a central role in shaping a new domain within a rapidly growing business and product lineup.
【Responsibilities】
Lead the architecture design and technology selection for the Sales Enablement AI Agent domain from the ground up
Lead the design and development of AI agent features that support the pre- and post-sales processes
Build the LLM/agent infrastructure (prompt design, RAG, context management, etc.)
Design and implement the front-end experience for navigation from the global menu
Design authentication and data integration with the BizClo common platform
Design and improve operational aspects, including infrastructure, performance, and reliability
Establish a development workflow that fully leverages LLMs such as Claude
Lead and mentor 1–2 development team members to be assigned in the future
Collaborate closely with the Product, Design, AI, and Infrastructure teams
【Expectations for This Role】
・A strong desire to plan and build products that directly drive tangible business outcomes for clients.
・The ability to balance high-speed iteration with stability and quality within the financial domain.
・Drive architectural design and technology selection with full ownership and autonomy from the ground up.
・Eagerness to pioneer AI agent development and embrace next-generation development workflows powered by LLMs.
【What You Can Gain in This Role】
・The opportunity to build and scale a brand-new domain within a rapidly growing business and product lineup from scratch.
・An environment where you can leverage an established platform used daily by tens of thousands of employees across major financial institutions from Day 1 to accelerate product growth.
・High autonomy to define and establish next-generation engineering processes powered by modern LLMs, such as Claude.
・An international environment that allows you to build cross-functional teams and drive product development alongside internal global team members.
・High ownership, high autonomy, competitive compensation, and flexible working arrangements.
Career Paths & Growth Opportunities
・Leverage your zero-to-one business launch experience to step into technical leadership and software architecture roles.
・Transition into engineering management and leadership positions as the core engineering team expands.
・Influence company-wide AI adoption and strategy based on deep technical expertise gained in LLM and AI agent development.
-------------【 Requirements】-------------
【Required】
5+ years of practical experience as a software engineer
Extensive full-stack development experience with modern web applications
・Experience in front-end development using React, Next.js, etc.
・Experience in back-end development using Node.js, Python, etc.
Experience in design and operations that takes infrastructure and performance into account
Ability to carry out architecture design and technology selection from scratch
Resides in Japan and has business-level Japanese proficiency
Experience and motivation to lead a team of 1–2 people
Ability to proactively drive projects forward even in highly uncertain situations
【Preferred】
Experience developing applications using LLMs and AI agents
Knowledge of RAG, prompt engineering, and dialogue design
Experience developing products in the financial sector or sales support field
Experience developing scalable SaaS platforms
Interest in and practical experience with AI-assisted development workflows (e.g., Claude)
Ability to communicate in English
【Ideal Applicants】
Hands-on experience developing application software utilizing LLMs and AI agents.
Technical knowledge of RAG (Retrieval-Augmented Generation), prompt engineering, and conversational flow design.
Experience in product development within the financial sector or sales enablement domain.
Proven track record in developing scalable SaaS platforms.
Strong interest in and practical experience with AI-assisted development workflows (e.g., using Claude, GitHub Copilot).
Business-level English communication skills for collaborating with global team members.
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【Welfare】
・Transportation allowance (bicycle commuting permitted)
・Company-issued laptop provided
・Company-issued mobile phone provided ※For certain positions only
・Flexible start time system (may apply every 2 months)
・Social insurance (Health Insurance, Employees' Pension Insurance, Employment Insurance, Workers' Accident Compensation Insurance)
・Life and health support leave
・Health checkup costs covered
・Childbirth and childcare support system
・Club activities
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