Leading the engineering team at CLASS101- Defined the engineering career ladder with clear expectations for each level, aligning engineers with their current roles and providing growth roadmaps to facilitate progression.- Improved operational excellence by building an automated alert system and incident response process, significantly reducing detection and response times.- Cultivated a culture of ownership by enabling engineers to lead projects, utilizing and refining methodologies like Scrum and Shape Up, resulting in high satisfaction among team members and stakeholders.

03/2023 - 09/2023 Website Platform & Mobile Platform09/2023 - 04/2024 Commerce Platform- Merged fragmented web and mobile design systems into a unified framework, promoting isomorphic design and eliminating redundant code, while implementing UI review and versioning processes.- Transformed mobile app pages from a WebView to native by using our design system, steadily improving performance.- Automated the mobile app deployment pipeline and established distinct release channels, allowing other teams to easily modify and deploy apps.- Designed a global marketplace platform capable of handle both physical and digital goods with one-time and subscription payments, inventory management, fulfillment, and payouts.

Advanced the company’s web and frontend technology to new heights.- Improved all core web vitals to recommended "Good" levels through techniques like SSR, SWR, SSG, bundle optimization, script/image loading strategies, layout improvements, and server-side authentication.- Developed a no-code page builder, ‘Document Builder,’ facilitating the creation of one-off promotional pages by enabling engineers to create reusable components for marketers and content editors, now handling over half of CLASS101's traffic.- Created an internationalization system supporting multi-region, multi-language markets (U.S., Japan, Korea) without disrupting core development workflows.- Defined GraphQL best practices to mitigate common mistakes across the organization and led the transition from a monolithic GraphQL server to a microservices architecture using Apollo Federation, implementing Supergraph and Subgraph structures for independent team development.Also, as a manager:- Conducted regular 1:1 meetings to provide feedback, align on expectations, and support engineers' growth.- Organized weekly team reviews to celebrate achievements, monitor progress, and promote continuous improvement.- Encouraged team members to recognize and lead essential work processes, such as design reviews, post-mortems, and daily stand-ups, by facilitating productive discussions around various case studies.

Led the Frontend Chapter of 15 engineers, setting goals for frontend engineering across the company and driving key initiatives.- Proposed an enterprise frontend architecture, define a code review guide and best practices to ensure consistent code quality across diverse teams.- Led the development of the design system by building a system that enables core platform engineers to easily create and expand design systems. Worked closely with designers, engineers, and PMs to ensure broad adoption.- Drove the adoption of modern frontend technologies, including monorepos, server-side rendering, and Webpack, while optimizing build and deployment pipelines.

- Built Korea’s #1 language learning application, 'Cake.'- Developed various features including OAuth for social login, role-play conversations, and expression sharing through the website.

- Built Korea’s leading mobile writing application.- Designed and implemented all features across Android, iOS,web and backend.

- Built Korea’s leading private tutoring service.- Designed and implemented a wide array of features across Android, iOS, web, and backend.