- Developed Android, iOS, and web frontend of a company analytics service DeepSearch using Flutter. Was in charge from the inception of the planning.- Designed the entire project structure to debug-friendly and minimize side effects by introducing Redux and Hook patterns and ensuring data immutability.- Reduced websites’ FCP, TTI time, and server cost by static site generator.

- Built the team, secured government investment, and founded the corporation. Cultivated a lean, trust&result-oriented culture that enables full remote work.- Led development of Flexpace, a timeline service for flex-time using React.- Designed the entire frontend project structure that ensuring inference-friendly typing, guarantees data immutability and integrity with normalization, and memory leak-free cancelable asynchronous job with ReactiveX.- Minimized redundant logic and establish code uniformity through abstraction. For example, Epic creator that schedule action queues and build cancelation structure, Hook that makes HTML elements to the infinite scrollable containers.- Introduced unit, UI testing, and asynchronous testing using Marble Diagrams.

- Developed Channel Plugin, a JS SDK for live chat, and a single page-based frontend of Channel Desk, an all-in-one business messenger. Participated from beta until grows to paid service of 26M daily exposures and 10K DAU.- Optimized performance through the batch update and rate limiting due to the frequent rendering by WebSocket. In addition, chat view improved 3x performance by implementing a virtual list, model optimization, and caching virtual DOM to prevent re-render and reflow.- Made structural improvements to reducing bugs by introduced Storybook for UI testing, migrated React class components to functional and TypeScript.- Enhanced team’s development productivity by implementing custom ESLint rules and increasing CI/CD speed by caching and Webpack optimization.

- Developed web frontend of Remember, business card management, and networking service. - Was in charge of developing business SNS, card book for the team, internationalization, and rebranding projects from the inception to the release.- Introduced React and migrated gradually from Angular 1.0 by configuring a coexistence environment.- Developed several static sites including landing page and separated that in main web application into a stand-alone project based on Next.js.- Improved team’s development productivity by creating developer tools including string extractor from JS, JSX, and HTML codes and boilerplate code generator.