This role is focused on building AI-powered tools that support sales enablement. As a Software Engineer, you will work on designing and developing product features that leverage AI technologies to improve how sales teams operate and create value for users. This is a high-impact position for engineers who are excited to work at the intersection of product development and applied AI.
Technologies
- AI/LLM: OpenAI SDK, prompt engineering & optimization
- Backend: Node.js, TypeScript, Effect (functional TypeScript)
- Cloud: AWS (Lambda, DynamoDB, SQS, SNS, SES, CDK)
- Integrations: Google APIs (Gmail, Calendar), Microsoft Graph API, Zoom API
- Testing: Vitest
- CI/CD: GitHub Actions, pnpm
Note: The above technologies reflect our current stack. The Agent team has the autonomy to make technology choices that best serve our AI-native product goals. You will be involved from the architecture and technology selection stage for new agent products.
Responsibilities
- Design, build, and operate AI agent systems powered by large language models (LLMs), including prompt engineering, output parsing, and evaluation pipelines
- Architect event-driven workflows (Lambda, webhooks, queues) that enable agents to act autonomously and reliably at scale
- Collaborate closely with product, sales, and CS teams to translate business needs into intelligent agent behaviors
- Own the full lifecycle of agent products — from prototyping and prompt tuning to production deployment and monitoring
- Evaluate and integrate new AI capabilities (models, APIs, tooling) to continuously improve agent performance
- Contribute to engineering best practices through code reviews, documentation, and knowledge sharing
Requirements
- 4+ years of software engineering experience in product development
- Hands-on experience building applications that integrate LLMs (e.g., Claude, GPT) — including prompt design, tuning, and output evaluation
- End-to-end engineering experience from design and development through to production operation
- Solid backend engineering skills (Node.js/TypeScript preferred)
- Experience with event-driven or serverless architectures (Lambda, webhooks, message queues)
- Strong communication skills and comfort working with cross-functional stakeholders
- Business-level proficiency in both Japanese and English (for Japanese, a JLPT N2 or higher certification is required).
- Passion for continuous improvement and staying current with the rapidly evolving AI landscape
Nice to haves
While not specifically required, tell us if you have any of the following.
- Experience designing, building, and operating architectures on AWS
- Familiarity with RAG (Retrieval-Augmented Generation) patterns, vector databases, or embedding-based search
- Experience building multi-step AI workflows (e.g., tool use, chain-of-thought, planning)
- Knowledge of SOLID principles, Clean Architecture, or Domain-Driven Design (DDD)
- Test-Driven Development (TDD) experience
Compensation
¥7,000,000 ~ ¥10,000,000 annually.
