Developed [Smatch], a commercial real estate matching service (React, NextJS)- Led the unification of the increasingly complex frontend-backend communication flow, layered with multiple legacies, by adhering to Relay's conventions. Tracked and visualized issues from the application level down to the database level, and involved the entire development team to redesign related domains in compliance with Relay's specifications.- Developed a complex multi-step form flow that generates proposal files using building/property information. This reduced the average proposal creation time from over 20 minutes to around 5 minutes, contributing to operational efficiency.- Consolidated and documented key real estate domain concepts such as NOC and office zones, which were fragmented across various materials. Discovered and corrected misimplemented formulas in the code during this process, and conducted multiple sync meetings to elevate the product team's domain understanding to the same level.- Developed a GitHub Action that reads PRs and commit messages during deployment to notify via Slack which tickets are being deployed. This replaced the inefficient tracking process of manually creating threads for each deployment.

Developed [Buildy], a building management/acquisition/disposition service (React, Remix, React Native, Expo)- Developed all features of the Buildy app service (managing my buildings, building search, community, etc.) from start to finish. As the only developer on the Buildy team until the initial launch, I contributed 100% to the entire development process, including frontend, backend, infrastructure, and CI/CD.- With the addition of a designer, I removed MUI—which was becoming technical debt due to cumbersome customization and low performance—and completely revamped the existing admin interface based on TailwindCSS. During this process, I improved the FCP (First Contentful Paint) on low-spec computers by up to 5 times.- Since the ChannelTalk SDK we used as a CS channel did not support Expo at the time, I created a custom plugin that injects the ChannelTalk SDK into the iOS/Android codebase at build time.- To eliminate the inconvenience of manually downloading SVGs from Figma screens during development, I created and published an npm library that allows easy use of SVGs from Figma in React and React Native, and applied it to internal products.- When developing the GPT-based "Buildy AI" feature, I built a simplified version of RAG (Retrieval-Augmented Generation) using building and property-related data, thereby overcoming the 4,096-token limitation of the OpenAI GPT model at that time.

Developed the [Ussist] app, a U.S. college admission assistant service (React Native)- Handled the entire development process of the Ussist app, including frontend, backend, and infrastructure.

Developed features within the [Readers] app, a reading record and sharing platform (React Native)- Replaced the existing book search feature — which used a combination of the Aladin API and simple LIKE queries — with an Elasticsearch environment, improving search speeds from an average of 3 seconds to under 1 second.