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Jihwan Kim

Jihwan Kim

Frontend-leaning Full-stack Engineer

  • React
  • Next.js
  • TypeScript
  • Electron
  • Product Delivery

Summary

I build B2B SaaS, global commerce, and Electron operations tools with React and Next.js. My work connects user-facing features with real-time systems, performance, testing, CI/CD, and production delivery.

“I find operational bottlenecks and solve them with software people actually use.”

Skills

Frontend
TypeScript / JavaScript / React / Next.js / React Query / Zustand / Tailwind CSS
Desktop & Realtime
Electron / IPC / Socket.IO / STOMP / NFC card readers
Backend
Node.js / NestJS / Python / FastAPI / Prisma / PostgreSQL / pgvector / REST API
Quality & Delivery
Playwright / Storybook / Docker / Cloud Run / Supabase / GitHub Actions / AWS S3 / CloudFront / macOS Notarization

Experience

Double T / Full-stack Developer, Frontend Focus

Built B2B groupware SaaS, a global commerce platform, and internal operations tools across user interfaces, real-time communication, operator workflows, and delivery infrastructure.

  • Moved NFC badge and menu operations from developer database edits to operator self-service
  • Reduced chat-room creation from 6s to 0.1s and duplicate IPC listeners from 134 to 15
  • Refactored 800+ i18n usages and reduced Storybook builds from 28.9s to 13.9s

Taebeknet / Frontend Developer

Built the tebekAI image-processing SaaS in a two-person team, covering image workflows, authentication, payments, and administration.

  • Delivered five AI image-processing services and their shared workflow
  • Implemented Toss Payments credit payments and user/admin authorization
  • Integrated Korean National Police and Kakao Search APIs

Selected Projects

Double U Works Groupware SaaS / Frontend Development

Built business domains and an Electron chat app, improving data retention, response time, application structure, and release reliability.

  • React
  • TypeScript
  • React Query
  • Zustand
  • Electron
  • Socket.IO
  • IPC
  • Playwright
  • GitHub Actions
  • AWS
  • HR, attendance, approval, ERP, CRM, and PMS interfaces
  • Automatic approval-draft saving
  • Refresh Token migration to httpOnly cookies
  • Chat-room creation: 6s → 0.1s
  • IPC listener registrations: 134 → 15
  • FCP: 3.1s → 2.2s
  • GitHub Actions and S3/CloudFront release pipeline
  • Windows code signing and macOS notarization

JHWorks AI Groupware / Product Design, Frontend & Backend Development

An independent groupware project connecting expense requests to missing-fact questions, policy evidence, previews and approvals. A token-based work home sits on server-validated permissions and business state transitions.

  • Next.js
  • TypeScript
  • FastAPI
  • PostgreSQL
  • pgvector
  • OpenAI API
  • Cloud Run
  • Supabase
  • Docker
  • CES expense settlement with evidence-linked missing/duplicate checks
  • Design tokens, responsive work home and keyboard shortcuts
  • Approval state transitions and optimistic concurrency
  • Deterministic leave calculation and employee-scoped reads
  • Policy RAG, Structured Output and restricted Function Calling
  • Explicit confirmation, idempotent saves and separate submit confirmation
  • Private Cloud Run / Supabase deployment and isolated backup restoration
  • Visitor data isolation, expiry and database-backed request budgets

Jikguround Global B2B/B2C Platform / Frontend Development

Built search, transaction, real-time chat, localization, and search-discovery systems for a global cross-border commerce platform.

  • Next.js
  • React
  • TypeScript
  • React Query
  • Tailwind CSS
  • next-intl
  • STOMP
  • tiptap
  • Storybook
  • JSON-LD
  • Unified product and supplier search
  • B2B quotation and settlement PDF/Excel generation
  • STOMP 1:1 chat with a WebSocket-specific token
  • i18n namespace and CI validation
  • Plate.js to tiptap editor migration
  • Three-language SEO and metadata rules

Game Park / Full-stack Design & Development

Designed and built a full-stack game platform where independent web games connect through a shared integration protocol.

  • TypeScript
  • React
  • Next.js
  • NestJS
  • Prisma
  • PostgreSQL
  • Socket.IO
  • Canvas
  • Designed an iframe + postMessage game integration protocol
  • Built a Next.js, NestJS, Prisma, and PostgreSQL full-stack architecture
  • Implemented Socket.IO matchmaking, multiplayer, and rankings
  • Handled Canvas game loops and deterministic state
  • Created a boilerplate for consistent new-game scaffolding
  • Released Kaboom, Handle, Mythology Defense, and Nemo Nemo Puzzle

In-house Cafe Operations Tool / Full-stack Development

Proposed, built, and deployed an Electron tool that enabled HR and cafe operators to manage employee badges and menus without developer intervention.

  • Electron
  • TypeScript
  • IPC
  • REST API
  • NFC
  • macOS Notarization
  • NFC-based employee badge registration
  • Member, badge, and menu CRUD
  • Electron, REST API, and hardware integration
  • macOS packaging and notarization

tebekAI / Frontend Development

Built upload, processing, results, authentication, payment, and operations flows for an AI image-processing SaaS in a two-person team with a designer.

  • React
  • JavaScript
  • React Query
  • React Router
  • Axios
  • Recharts
  • Toss Payments
  • CSS Modules
  • Five AI image-processing experiences
  • Shared upload-processing-result components
  • Credit payments with Toss Payments
  • User and admin authorization

Oreuda — GitHub Management Service / Frontend Development

Built a Chrome Extension, landing page, and Markdown parser for a developer-focused GitHub management service.

  • Next.js
  • React
  • TypeScript
  • Chrome Extension API
  • Chrome Extension development and Web Store release
  • README parser converting GUI output into Markdown
  • Landing page and GitHub-integrated user flow

Training

Samsung Software Academy for Youth

Cohort 8, Web Development

Completed web development training and team projects with Java, JavaScript, MySQL, Spring, and React.