Frontend Development using React, TypeScript.- transitioned current repository to monorepo, deployed private UI library through GitHub Packages and applied to each repositories.- transitioned the architecture to Feature-Sliced Design(FSD).- implemented real time collaboration tool(CAT Tools) using WebSocket. - using windowing to optimize for thousands of objects.- implemented CDD by adding Storybook(https://storybook.beringlab.com). - added interaction test codes for UI components using @storybook/test. - added GitHub Actions script of interaction test automation for Storybook using Playwright.- added unit test codes using @testing-library/react and vitest.- implemented state management and validation for complex forms using React Hook Form and Zod.- implemented real-time translation, queuing, notification using SSE.- refactored whole UI components using @shadcn/ui.- linked payment system using Toss Payments SDK(Korea), Stripe(Global).- added Sentry to collect error logs.

Frontend Development using Next.js, TypeScript, Working on e-commerce project Harmony. Launched 5 marketplaces.- in charge of all client processes from product creation to registering them on each marketplace, the basics of e-commerce.- refactored data fetching using React Query's useQuery and useMutation by considering reusability during the process and created Custom Hooks.- improved user experience by inserting search results into the URL using next/router so that the search results are maintained even when events such as refreshing.- removed our own ui component library to reduce page size by integrating the only components used directly into the project, saving over 100KB per page.- re-wrote Azure DevOps Pipeline script after Yarn Berry migration and deleting unused, unnecessary packages, resulting in approximately 37% reduction of CI time.- led automated deployment process migration from Serverless framework to AWS Amplify, resolving compatibility issues with the latest technologies such as Next.js 13 and resulting in approximately 44% reduction of deployment time.- added i18n feature(including English translation) for global use with next-intl.- added debounce function to reduce re-rendering.