Software Engineer at Google

Designed and enhanced large-scale advertising platform capabilities for YouTube Ads across TypeScript/JavaScript product surfaces and cloud-based services. Improved critical application and service performance through frontend optimization, service-level tuning, and more efficient platform interactions, achieving ~25% faster response times for selected workflows. Strengthened production readiness via monitoring, operational improvements, CI/CD practices, and structured code-quality reviews, reducing recurring delivery and operational issues by ~20%. Partnered with product managers, data scientists, and engineers to translate product requirements into technical solutions while balancing MVP delivery with scalability and production risk. Improved developer workflow and reusable platform patterns, reducing repetitive implementation effort by ~20%. Applied automated validation and review practices for production changes to support maintainable code, reliable releases, and safe evolution of

Software Engineer at Mercari

Developed customer-facing search experience features for a major Japanese e-commerce marketplace using React, TypeScript, JavaScript, and API-driven application architecture. Improved search workflow responsiveness via frontend performance optimization, efficient service interaction, and caching-oriented improvements, reducing selected user-facing response times by ~25%. Refined reusable frontend patterns and application behavior to improve maintainability and reduce regression risk by ~15% across targeted search features. Collaborated with product, frontend, backend, search, and data teams to turn requirements into practical customer functionality and resolve technical trade-offs. Participated in testing and production deployment activities, improving release quality and reducing recurring implementation issues by ~20%.

Software Engineer at SmartNews

Built reusable React and TypeScript frontend components and shared platform capabilities supporting multiple SmartNews web products. Modernized frontend architecture and shared application patterns, reducing duplicated implementation effort by ~30% and improving consistency across product teams. Improved application performance and maintainability through targeted frontend optimization and architectural refinement, achieving ~20% faster performance in selected user-facing workflows. Collaborated with platform engineers and product teams on technical design, implementation decisions, testing, and incremental modernization of shared web foundations.

Software Engineer at PayPay Corporation

Led development of key frontend features for PayPay consumer applications, owning implementation from product and design requirements through deployment and post-release monitoring. Delivered customer-facing payment experiences using modern JavaScript and React-oriented frontend development practices with emphasis on usability, performance, and reliable interaction flows. Improved frontend performance and user experience through targeted optimization, reducing selected page and interaction processing times by ~20%. Collaborated closely with product managers, designers, QA, and engineering teams to resolve implementation and product issues, prioritize delivery, and maintain quality across business-critical payment features. Contributed to engineering reviews and mentoring, helping improve implementation consistency and reducing recurring frontend defects by ~15%.