Software Engineer (Middle Level), Search Ads Group - Ad Product Development Department (GATD)

The Ad Product Section (APS) division is a high-performance, global team distributed across Tokyo, Singapore, India, and China.

We pride ourselves on being a hub of technical excellence, where motivated, diverse, and talented engineers collaborate to solve complex problems at scale.

We are seeking a Senior Software Engineer to join our team and help us define the next generation of our advertising platform. This is not just a coding role; it is a position of architectural and technical cultural leadership.

You will own the end-to-end product development lifecycle, leveraging a modern tech stack and AI-augmented workflows to deliver high-impact solutions.

We are looking for a technologist who doesn't just keep up with the industry, but shapes it - someone who thrives on building scalable systems, mentoring the next generation of engineers, and integrating AI to push the boundaries of productivity and software quality.

If you are a builder who values technical rigor, thrives in cross-functional environments, and is eager to contribute to Rakuten’s expansive global ecosystem, we want to talk to you.

Technical Leadership: Translate complex business requirements into robust, scalable, and maintainable technical specifications and architectural designs.

Lifecycle Ownership: Own the full SDLC - from initial design and implementation to deployment, monitoring, and proactive maintenance across all environments.

Quality Assurance: Conduct rigorous code reviews, ensuring adherence to design patterns, security best practices, and long-term maintainability.

AI-Augmented Development: Drive engineering velocity by integrating AI-powered coding assistants (e.g., GitHub Copilot, Cursor) into the team’s workflow. Establish standards for AI-assisted code generation, ensuring that AI-written code is rigorously vetted for security, accuracy, and alignment with system architecture.

System Stewardship: Maintain a deep understanding of the product ecosystem to identify technical debt and architectural bottlenecks. Proactively propose and lead initiatives to refactor or enhance systems for better performance and scalability.

AI-Driven Productivity: Leverage advanced prompt engineering to automate repetitive tasks - such as documentation generation, legacy code refactoring, and test suite creation - to maximize team bandwidth.

Tech Radar: Stay ahead of the curve by evaluating emerging technologies and AI tools, creating strategic roadmaps to integrate innovations that provide a competitive advantage.

Partnership: Act as the primary technical bridge between Product, Design, and Engineering. Translate high-level business objectives into clear, actionable technical plans.

Technical Advocacy: Influence product roadmaps by anticipating future technical constraints and opportunities, ensuring the platform remains resilient as business needs evolve.

Team Growth: Actively mentor junior engineers and interns. Foster a culture of technical excellence by providing constructive feedback, guiding career progression, and promoting best practices in software design.

Knowledge Sharing: Champion a culture of continuous learning, ensuring the team stays informed on modern development paradigms and AI-assisted workflows.