TECH-EN-110 Software Engineer, Backend - AI Agent

We are a legal AI company that combines deep legal expertise with advanced capabilities in artificial intelligence. Since our founding in 2017, we have focused on developing AI-powered LegalTech solutions, raising over ¥17.9 billion in funding to date. In 2022, we established a U.S. subsidiary to accelerate our international expansion, continuing to grow at a remarkable pace. Our flagship product is “LegalOn Cloud,” an AI-powered legal operations platform that comprehensively supports in-house legal teams across a wide range of workflows. Internationally, we have launched “LegalOn Global,” our AI contract review service, in both the U.S. and U.K. markets. In addition, we are actively exploring new business domains. In 2025, we released “AI Counsel CorporateOn,” a generative AI solution purpose-built for corporate teams, enabling one-click access to internal policies and company-wide legal insights. Our products leverage advanced natural language processing technologies, including machine learning algorithms and large language models (LLMs). We also incorporate proprietary innovations such as our “Legal Document Graph”—a structured knowledge base of legal content—and autonomous AI agents that can plan and execute tasks. These capabilities enable us to deliver cutting-edge user experiences and highly sophisticated solutions. For more details about our company, products, and development organization: https://legalforce-recruit.notion.site/LegalOn-Technologies-3e114a8aecfb410a96424e34a0ed8bd6 We are currently building a new product from the ground up that centers around AI Agents, delivering a radically new user experience. AI Agents are intelligent tools that understand users' natural language, create plans, and autonomously execute tasks to completion on their behalf. This product is being built from scratch, and the backend plays a critical role in orchestrating LLMs, tools(MCP), custom workflows, agent's long/short term memory, and user data with reliability and flexibility. To succeed, we need backend engineers who are not only technically strong but also product-minded and eager to tackle ambitious challenges alongside a cross-functional team. If you’re excited about shaping the backend of intelligent, task-completing agents - while balancing speed, scale, and safety - we’d love to hear from you. 【Key Responsibilities】 You will take ownership of designing and developing the backend architecture for our AI Agent product. This includes implementing APIs that interface with agent engine, managing session storage, message queues, database and other backend components, ensuring robustness of task execution, and designing data models that reflect real-world agent behavior.As an early team member, you'll also be deeply involved in architecture design, technology selection, and team culture. This is not a “build to spec” role—you’ll collaborate closely with designers, product managers, and AI engineers to iterate quickly and deliver user-impactful features. ■What Mission and Challenges you’ll take on - Designing and developing core features to realize AI agents that can complete real-world tasks—not just engage in conversation - Designing and building a backend foundation from scratch, free from existing constraints and with a clear vision for the product’s future ■What You’ll Do - Design and develop backend systems for a new AI Agent product from the ground up - Build APIs, task orchestration systems, and data models that support dynamic, goal-driven agent behavior - Integrate external tools and internal components (LLMs, workflow engines, etc.) - Ensure reliability, observability, performance, and scalability in production environments - Contribute to automation, testing, documentation, and engineering process improvement - Mentor junior engineers and contribute to team growth ■What Makes This Job Rewarding - Collaborate as equals with product managers and business stakeholders as part of a unified team - Gain valuable decision-making experience in a fast-growing company where you will be trusted with significant ownership and influence over business, technical, and process direction 【Development Environment / Tools】 Backend：Python, Go ▼We have compiled information about development environments and tools for our other products on Notion. https://legalforce-recruit.notion.site/LegalOn-Technologies-f5ebe38a6009428ab0fb1714efd3c90a

Required Skills / Qualifications - 3+ years of professional experience in backend development for web applications - Proficiency in programming languages such as Python, TypeScript, or Go - Experience designing and implementing APIs (e.g., REST, WebSocket) - Experience in designing and operating databases such as PostgreSQL, MySQL, or MongoDB - Basic knowledge of microservices, distributed systems, and asynchronous processing - Ability to work autonomously in collaboration with cross-functional roles such as product managers, designers, and AI engineers - Japanese language proficiency equivalent to JLPT N3 or above

Preferred Skills / Qualifications - Foundational understanding of LLMs or AI Agents, or experience developing related products - Experience in session management, job scheduling, and queue processing (e.g., Redis, Kafka, SQS) - Knowledge of infrastructure tools such as Docker and Kubernetes - Experience with CI/CD pipelines, test automation, and observability/monitoring tools - Experience in designing and reviewing systems with a focus on security and scalability - Hands-on experience in early-stage startups or new business development environments - Strong communication skills, with the ability to work effectively across diverse cultures in both English and Japanese

Ideal Candidate - Proactive communicator who collaborates well and thinks through the why and what behind every development effort - Flexible thinker who solves problems beyond their comfort zone or specialty area - Respectful and team-oriented contributor who works for the success of others, not just their own - Growth-oriented individual who is eager to learn and willing to put in the effort to improve