Senior Software Engineer

Background Real estate is deeply connected to nearly every aspect of our daily lives. Whether it's shopping malls, hotels, logistics warehouses powering e-commerce, or data centers supporting the digital world, economic activity always takes place somewhere. At estie, we view real estate as the foundation where economic activity happens, and we're committed to enriching people's lives through the power of data and technology. Commercial real estate—including office buildings, logistics facilities, and shopping centers—is one of the largest asset classes in the world. Tokyo holds the largest stock of institutionally owned commercial real estate globally, making Japan one of the world's most significant markets. Despite its scale, much of the industry's information remains fragmented and inaccessible, creating barriers to better investment decisions and urban development. What if people around the world could recognize the true value of Japan's cities and allocate resources based on reliable data? We believe this could unlock new economic opportunities and help create globally competitive cities. At estie, we are transforming the commercial real estate industry by making information, operations, and transactions more seamless through technology and data. To achieve this vision, we continue expanding our portfolio of products and businesses while tackling increasingly complex technical challenges. As our organization grows and our product portfolio expands, we face challenges involving real-time data integration across products, complex domain modeling for commercial real estate, production deployment of AI-powered functionality, and security for highly sensitive real estate data. We are looking for engineers with deep technical expertise who can solve these challenges and amplify business value through technology. About the Role We expect Senior Software Engineers to bring deep expertise in one or more technical domains while applying that expertise to drive tangible outcomes for both product teams and the business. This role goes beyond solving technical problems through implementation. You'll help elevate the technical capabilities of engineering teams, influence architecture and strategy, and contribute wherever necessary to ensure product success. Why This Role Is Exciting Develop deep expertise in a technical domain while directly influencing product and business outcomes Work with uniquely complex real estate data, collaborating closely with customers and domain experts to transform real-world complexity into elegant system designs Tackle challenging technical problems, including production deployment of AI-powered features and security architecture for highly sensitive real estate data Influence technical decisions across more than ten products, where architectural choices can have company-wide impact Help evolve a platform trusted by over 90% of major Japanese real estate developers and J-REITs Responsibilities You will primarily work on high-impact technical challenges such as: Designing architectures for real-time data integration across multiple products Collaborating with customers and domain experts to model complex real estate concepts and translate domain knowledge into scalable data models Designing, deploying, and operating production systems powered by machine learning and Large Language Models (LLMs) Designing security architectures and managing risks for products handling highly sensitive real estate data Building and launching new products rapidly while balancing experimentation, validation, and long-term maintainability Team Structure This is a cross-functional role that works across multiple engineering teams. You'll collaborate with engineers throughout the organization while helping shape company-wide technical foundations and architectural direction. You'll have opportunities to discuss and refine technical strategy directly with the Company CTO and Business Unit CTOs, enabling broad influence across the engineering organization. Tech Stack Frontend Next.js React TypeScript Backend Depending on the product, one or more of the following stacks are used: Rust + Actix Web + Async GraphQL Ruby on Rails TypeScript + Node.js + NestJS GraphQL is used as the primary interface between frontend and backend services. For internal analytics tools: Python Streamlit Development Tools GitHub GitHub Actions Sentry Datadog Jira Slack GitHub Copilot Claude Code Cursor Devin Codex Required Qualifications We welcome candidates who possess deep expertise in at least two of the following areas, or exceptional expertise in one area. 1. Software Architecture Experience making and owning significant architectural decisions across multiple systems throughout their lifecycle Deep understanding of multiple programming languages, frameworks, and architectural paradigms Ability to evaluate and select appropriate technologies based on business and technical requirements 2. Data Modeling & Information Architecture Experience designing, operating, and evolving complex domain-specific data models Experience collaborating with domain experts and customers to uncover implicit business knowledge and translate it into data models and information structures Strong understanding of design methodologies such as Domain-Driven Design (DDD) and Use-Case Driven Design, with the ability to apply them appropriately 3. Artificial Intelligence Experience taking machine learning or Large Language Model (LLM) features beyond proof-of-concept and into production operation and continuous improvement Strong awareness of emerging technologies and a track record of incorporating insights from conferences, research papers, or industry developments into real-world systems Ability to evaluate when AI should and should not be applied based on accuracy, cost, latency, and hallucination risks 4. Product Security Experience designing and operating security systems involving authentication, authorization, and data protection Experience incorporating threat modeling, secure coding practices, and vulnerability management into development workflows Ability to balance business risk, development velocity, and security investments 5. Technical Leadership & Rapid Product Development At least two years of experience working in teams with strong code review practices and a culture focused on code quality Ability to balance short-term delivery and long-term maintainability through sound engineering decisions Experience facilitating technical decision-making among stakeholders with differing viewpoints while maintaining focus on delivery outcomes Preferred Qualifications Development experience with Rust, TypeScript, or Ruby Experience designing and operating GraphQL APIs Experience building and operating services on AWS Experience working in multi-product environments Who We're Looking For Someone who challenges assumptions and focuses on maximizing business value regardless of formal role boundaries Someone who is passionate about turning deep technical expertise into meaningful product and organizational outcomes Someone who willingly steps beyond their defined responsibilities when necessary for product success Someone who proactively questions existing approaches and drives continuous improvement