React Router · TanStack Query Contributor

Younghoon Kim

Frontend Engineer

I am a frontend engineer focused on React, TypeScript, and Next.js. I have worked on stabilizing user flows under high traffic, performance optimization, and legacy migrations. I have contributed to open source projects including TanStack Query and React Router with 10 merged PRs included in official releases.

Experience

Work history

EA Korea

Mar 2025 - Present

Frontend Engineer — FC Online Operations Tool

React, Zustand, TanStack Query, React Router, Zod, nuqs

  • Reduced weekly QA reproduction/log request tickets from 10 to 3 by syncing URL state.
  • After redesigning the item version-management flow, similar deployment issues dropped to zero.
  • Owned the end-to-end frontend workflow (stack selection, QA collaboration, and documentation).

NHN Injeinc

May 2024 - Mar 2025

Frontend Engineer — Ticketlink

React, Zustand, TanStack Query, React Router, i18next

  • Built reservation flows for large-traffic events such as KBO Opening Day and the Korean Series.
  • Unified JSP-based multilingual pages into a single React + i18next codebase (2 -> 1).
  • Blocked non-eligible users from entering booking flows via fan-club-tier and team-policy filtering.

PandoraTV

Jul 2023 - May 2024

Frontend Engineer — Cobak (Crypto Community)

React, Redux Toolkit, React Query, Next.js, Framer Motion, EJS

  • Improved Lighthouse SEO score from 56 to 82 using dynamic meta injection in EJS templates.
  • Developed a hybrid-app WebView flow for community and product purchase journeys.
  • Proposed and implemented @mention support end-to-end, including notification integration.

Skills

Tech stack

Core

ReactTypeScriptNext.js

State/Data

TanStack QueryZustandReact Router

Build/Test

ViteVitestPlaywrightESLint

Backend

Node.jsExpressFastifyPrismatRPC

Open Source

10 PRs merged to official releases

TanStack Query

GitHub
  • Merged

    Optimized useQueries from O(N²) to O(N) (#8641)

    Reduced function calls in the 500-query benchmark from 4,500 to 2,000 (~55%).

  • Merged

    Fixed persist + memoized combine bug (#9592)

    Resolved stale UI after page refresh.

  • Merged

    Fixed CI timeout (#9623)

    Stabilized mismatch in Nx Cloud distributed execution config.

React Router

GitHub
  • Merged

    Fixed missing middleware skipRevalidation handling (#14286)

    Prevented unnecessary parent loader re-executions.

  • Merged

    Handled restricted browser storage environments (#14335)

    Added safe handling for session save failures in private mode.

  • Merged

    Fixed fetcher.submit JSON bug (#14534)

    Added regression tests for SSR environments.

  • Merged

    Fixed generatePath suffix parameter handling (#14269)

    Resolved failures generating :id.json paths.

  • Merged

    Added crossOrigin attribute to <Links /> (#14687)

    Addressed CDN CORS CSS preload issues.

React Hook Form

GitHub
  • Merged

    Fixed useController type regression (#13150)

    Resolved never-lock issue and added type tests.

TanStack Router

GitHub
  • Merged

    Fixed params.parse notFound() handling (#5864)

    Changed 500 to 404 behavior and added tests.