Technology is just a tool.
What matters is creating value.

Leading the Frontend Mobile Chapter, a group of frontend developers building Toss's B2C consumer-facing services. I design the culture and environment where chapter members can work and grow as outstanding developers, handling recruitment, HR, and mentoring. Beyond that, I strategize how the Toss frontend chapter can establish itself as the most capable frontend group in the world.

Leading Toss's open-source committee, proposing growth and branding strategies to library owners, and creating a foundation for Korean developers to transform from consumers to producers. The goal is to open and share open-source projects with developers outside Toss, contribute to improving the technical capabilities of the domestic development community, and expand influence to the global open-source community.

Operating a hiring committee aimed at establishing unified standards and structured interview and verification systems across all Toss subsidiaries' frontend chapters, with the goal of recruiting colleagues with diverse strengths at minimal cost.

Introduced the concept of chapters as an organizational unit within the QuotaLab team and took on the DRI for building and operating the frontend chapter from scratch. Contributed to aggressive recruitment inflow, branding, and process establishment to achieve the mission of bringing in top talent and implementing a culture based on full autonomy and responsibility.

Proposed the need for a design system to increase team productivity, formed a guild to gather necessary personnel and drive the project. Used a strategy of introducing the most essential tokens first without disrupting business, then executing a 1-year roadmap for gradually adopting complex components.

Developed features enabling VC analysts and managers to conveniently manage portfolios and facilitate communication with target companies for investment deals, fund management, LP reporting, etc. Also conducted activities such as 1-on-1s for engineers' technical growth and career development, fostering intrinsic motivation.

Eliminated and improved difficulties and inconveniences that unlisted startups face in financial/legal contexts, including fundraising, business reporting, shareholder and board management, and stock option/RSU grants.

Served as an agile lead helping frontend developers in the silo responsible for Toss Core's innovative business improve their productivity and set growth directions. Led an organization of 5-6 frontend developers, focusing on resolving difficulties members faced and establishing growth directions that leveraged each person's individuality to maximize team synergy.

Developed products like pedometer, brand cashback, and lucky quiz that provide financial and daily life benefits to Toss users.

As an initial member of the Ads Silo — the first team within Toss to have advertising as its business domain — developed products within the benefits tab such as weekly missions and money alerts, as well as Toss Prime, Toss's membership service.

Developed the insurance service within the Toss app, supported subsidiary Toss Insurance with CRM development and frontend deployment/operations infrastructure using AWS, Travis CI, and Terraform. Focused on aligning Toss and Toss Insurance's infrastructure and development environments as closely as possible, so that any frontend developer from Toss could maintain productivity when supporting Toss Insurance.

Added notification features using Web Socket and Notification API to keep pros and consumers communicating within the Soomgo service, reducing churn rate and making it easier to check match status.

Improved FCP by approximately 70% through asset caching strategy improvements, bundle size reduction, and Critical Rendering Path optimizations.

Added ts-loader to the existing Vue application's build process to configure TypeScript builds, and proposed and executed a strategy to gradually increase type coverage without impacting business development speed, achieving type safety.

Migrated the build process from gulp & gulp-webpack plugin configuration to webpack-only bundling and transpiling.

Separated the frontend application from Django dependency and implemented an SSR render server using Express. At the time, Vue's ISR frameworks were not mature enough, so I chose to implement a minimal render server directly.

Expanded the 08liter service's i18n from English and Korean to 4 languages. The service was ultimately provided in English, Korean, Chinese, and Indonesian. During this process, defined and propagated work processes within the team to reduce unnecessary communication costs between developers and translators.

Conducted cross-browser testing for various browsers commonly used by Chinese users such as Weibo, QQ, and Cheetah, and integrated with Chinese SNS services via OAuth 2.0.

A mentoring project for junior developers and designers. Over 3 months, we developed toy projects together, aiming to grow both soft skills (communication, MVP definition, hypothesis validation for efficient collaboration) and hard skills (through code reviews and design critiques within chapters). Conducted 3 cohorts total, all free of charge.

A service for people looking for side projects to gain experience or study. Started as a side project to help people find toy projects matching their conditions or find team members. FE was built with Vue and TS, BE with Express, and some APIs as Serverless APIs using AWS Lambda.

Realized the Lubycon project's codebase had grown too large to maintain while working full-time, so I split out the Artwork section into a separate service. Built with AngularJS, and started using AWS and Docker for service delivery for the first time.

A WebGL-based 3D model web viewer and editor. Implemented a custom OBJ-to-JSON parser, texture application to geometry, internal light source creation, and material/specular settings. Self-studied vectors, tensors, Euler angles, and quaternions to understand object placement and rotation in 3D space.

A platform service for uploading and sharing artwork, vector sources, and 3D models on the web. All team members were self-taught non-CS majors who worked on this project to learn development. Initially built with jQuery and PHP, then migrated to AngularJS and Laravel.