Senior Software Engineer

The Senior Software Engineer addresses complex technical challenges across multiple commercial real-estate products. Responsibilities include designing real-time data integration between products, modeling and operating real-estate domain data in collaboration with customers and domain experts, designing and running production features that use machine learning and large language models, and designing security and risk responses for products handling confidential real-estate data. The role also involves rapidly launching products while testing hypotheses in parallel.

The position works across development teams with engineers from multiple teams and helps advance the company-wide technical foundation and architecture. Technical direction can be established through discussions with the company CTO and business-unit CTOs. The role is expected to apply deep expertise to business and product outcomes, contribute hands-on solutions, raise the technical capability of teams, and work beyond a narrow job scope when needed for product success.

The development environment includes Next.js, React, and TypeScript on the frontend. Backend environments vary by product and include Rust with actix-web and async-graphql, Ruby on Rails, and TypeScript with Node.js and NestJS. GraphQL is used for interfaces with the frontend, and shared components are separated into microservices. Internal analysis tools use Python and Streamlit. Development tools include GitHub, GitHub Actions for CI/CD, Sentry and Datadog for monitoring, JIRA, Slack, GitHub Copilot, Claude Code, Cursor, Devin, and Codex.

Applicants are expected to have at least two of the following areas of expertise, or exceptional depth in one: architecture; data modeling and information design; AI; product security; or rapid proof-of-concept implementation as a Tech Lead. Relevant experience includes making and operating architectural decisions across multiple systems, working with multiple languages and frameworks, maintaining complex real-world data models, extracting domain knowledge through customer and expert interviews, applying design methods such as domain-driven or use-case-driven design, taking machine-learning or LLM features through production and improvement, and incorporating current research into real systems. Product-security experience may include authentication, authorization, data protection, threat modeling, secure coding, vulnerability assessment and remediation, and prioritizing security investment against business risk and development speed. The Tech Lead profile includes at least two years of development in a team with active code review and experience balancing delivery, quality, technical debt, and differing technical opinions. Experience with Rust, TypeScript, Ruby, GraphQL API design and operation, AWS service development and operation, or multi-product development is welcomed.

This is a full-time, indefinite-term position with a three-month probationary period from the start date. The listed annual salary range is JPY 10,000,000 to 15,000,000; the body of the posting states that grade and compensation are determined individually under company rules. Monthly compensation includes base salary and a fixed allowance equivalent to 40 hours of overtime, with additional overtime, holiday, or late-night premiums paid when applicable. Bonuses and salary revisions may occur up to twice a year depending on company and individual performance.

The workplace is in Akasaka, Minato, Tokyo. The company recommends combining office attendance with remote work. The discretionary work system uses 10:00–19:00 as the basic schedule, with start and end times left to the worker; a one-hour break is provided when work exceeds six hours. Work beyond scheduled hours may occur. Holidays are Saturdays, Sundays, and public holidays, with 125 annual holidays, summer leave, Welcome leave, and year-end holidays. Benefits include stock options, flextime and discretionary work systems, remote work, housing and moving-cost assistance, and support for qualifications, books, and study events. Social insurance is provided, and a smoking room is installed.