Recruitment background
3DC is a startup transforming the battery and chemical industries through both hardware and software. Alongside our materials business, we are launching a solutions business that develops an AI platform purpose-built for R&D sites in the battery and chemical industries. Since August 2026 we have been developing Ver 1.0 together with an external development partner. To accelerate development and bring design, implementation, and operation in-house, we are hiring our first in-house software engineer.
Job description
Reporting directly to the CEO, you will own the technology selection, design, implementation, and operation of the backend and infrastructure of our AI platform. This includes SaaS platform design decisions such as multi-tenancy, authentication and authorization, and audit logging, as well as implementing AI features using LLM APIs, RAG, and MCP, and frontend development as needed. Because our own materials R&D team is the platform's first user, you will work alongside them on site and improve the product based on how it is actually used.
You will start by understanding the R&D workflows of battery and chemical development and the current state of the product, then join agile development with our external partner (one scrum master and two engineers) as a full-stack engineer. Over time, we expect you to lead the building of our engineering organization, including hiring the second engineer and beyond.
Required qualifications
･3+ years of experience in web application development
･Experience owning a single product from implementation through post-release operation and maintenance
･Knowledge and experience in the design, operation, and optimization of databases (SQL and NoSQL)
･Experience building CI/CD and IaC (Terraform, etc.)
･Experience using coding agents such as Claude Code and Codex in daily development
･Business-level Japanese (JLPT N1 equivalent)
Preferred qualifications
･Experience implementing AI agents with LLM APIs, RAG, MCP / Function Calling
･Experience launching a B2B SaaS product from 0 to 1 (from design through release and delivery to the first customers)
･Experience expanding a service overseas (internationalization)
･Domain knowledge of manufacturing, or experience developing systems for manufacturing / R&D (LIMS, ELN, MES)
･Experience in UI/UX design
･Experience in product management
Development environment
･Languages / frameworks: TypeScript, NestJS, Drizzle ORM, React, etc.
･Infrastructure: AWS, Terraform, PostgreSQL, etc.
･AI: Amazon Bedrock, etc.
･Development process: GitHub, GitHub Projects, etc.
･Communication: Slack, Notion, etc.
･Equipment: a PC and AI tools (coding agents, etc.) are provided by the company (specs and plans are negotiable)
Ideal candidate profile
･Interest in updating how R&D is done in manufacturing
･Ownership: treats the product's success as their own, without limiting their scope
･Willingness to actively learn the battery and chemical domain
･Flexibility, without attachment to specific technologies or past ways of working
･Teamwork and respect for members with different backgrounds
Full-stack engineer (tech lead candidate)
Full-time
Negotiable
Kanagawa, Japan (Shin-Kawasaki office, hybrid with office attendance encouraged)
3 months from the date of hire
･Comprehensive social insurance coverage.
･Housing allowance.
･Relocation allowance for single assignments.
･Travel allowance.
･Stock option program available.
Document screening → Interview (multiple rounds)
