AI-Driven Development Platform Engineer, Frontend and Design Systems

This role focuses on redefining development processes around AI and building the frontend foundations needed to support them. Responsibilities include defining requirements, designing, and implementing a design system and other shared frontend infrastructure. The engineer will also optimize APIs to improve performance and usability, and work with product development teams across the company to propose AI-supported processes and improve the speed and quality of UI development. Assigned responsibilities may change according to business conditions and suitability.

The required background includes experience improving a development process with AI agents, at least three years of software development experience including web frontend development, experience building applications with complex state management, and experience designing and implementing UI components. Candidates must be able to apply current AI-related information to practical work, implement robust software with TypeScript, and understand and use package managers such as npm, yarn, or pnpm. An understanding of general UI design principles, including considerations important for business systems, is required. Experience using component-oriented JavaScript libraries such as React, Vue, or Angular is also required.

The role involves proposing ideas and negotiating with company-wide and cross-team stakeholders, rather than limiting communication to the immediate team. It requires attention to end-user usability, developer experience for non-engineers and engineers, overall team productivity, technical debt reduction, scalable architecture, and the balance between implementation efficiency and usability. The engineer is also expected to identify underlying requirements from internal users of the design system and turn them into concrete designs.

Preferred experience includes UI design and implementation for business systems, backend development such as Ruby on Rails, OSS or community contributions, CI/CD environment development and operation, large-scale frontend application design and development, and building or operating a SaaS product design system. Project management, AI-agent orchestration, releasing AI-enabled OSS or services, agile development, design engineering, deeper TypeScript or React experience, mobile UI development, conference presentations, and developer-blog writing are also welcomed.

Additional preferred knowledge includes HTML, CSS, and JavaScript web standards, secure frontend implementation, accessibility, frontend performance tuning, domain and use-case modeling, and automated frontend testing.

The position is a regular full-time employee role with a three-month probationary period. The work location is the Tokyo office in Osaki, Shinagawa-ku, Tokyo. Working hours use a discretionary labor system with a deemed eight-hour workday. Holidays and leave include Saturdays, Sundays, public holidays, year-end and New Year holidays, condolence leave, paid leave granted from the start date, and six paid sick-leave days per year. Social insurance includes employment insurance, workers' compensation insurance, employees' pension, and health insurance. Indoor smoking is prohibited. The posting states that online interviews are available and that work location may change because of business circumstances or office relocation.