Jihwan Kim

Developed key domains (attendance, approval, HR) for groupware SaaS Double U Works and owned the chat desktop app end-to-end. Currently building the frontend for cross-border e-commerce platform Jikguround.

• Unified product · supplier search results page — SSR with tab, sort, and pagination synced to URL
• Real-time 1:1 chat client over STOMP — REST + WebSocket hybrid, migration to a WS-scoped token, transaction status and member-type-specific action events
• Storybook builder migration (webpack → Vite) — average cold build 28.9s → 13.9s (~2.08× faster), output size -23.5%
• Text editor replacement (Plate.js → Tiptap v2) — resolved mobile input and layout issues
• Chat room creation 98.3% faster (6s → 0.1s) — identified repeated request bottleneck and simplified structure
• Electron IPC socket optimization — duplicate subscriptions 134 → 15 (-88.8%), typing delay resolved
• Auto-save for electronic approval drafts — prevented session-expiry content loss, balanced save frequency and server load via debounce/throttle
• Playwright E2E · GitHub Actions CI/CD · AWS S3/CloudFront auto-deploy pipeline
• Code splitting (Lighthouse Performance 63 → 73, FCP 3.1s → 2.2s) · security (refresh-token migrated to http-only cookie)
• Claude Code team workflow — standardized role-specific commands and context, ~56% productivity gain (WBS basis)
• CES 2026 booth PO — sourced 3 partners

After SSAFY, sharpened skills through hackathons and side projects before joining to solely architect the entire frontend for AI image processing SaaS tebekAI. As a 2-person team with one designer, owned the full product lifecycle from planning through deployment, launching 5 AI services into production.

• Solely designed & built AI image processing SaaS frontend (tebeknet.kr)
• Implemented 5 services: missing child similarity, celebrity/artwork matching, art style transfer, etc.
• Built registration/login authentication & credit payment system
• Responsive design (mobile/tablet/desktop)
• Google Analytics & AdSense integration

Full-stack browser game platform powered by a 5-phase Claude Code agent pipeline. Built a game boilerplate system and rapidly shipped 2 multiplayer games — demonstrating AI-augmented development at scale.

• TypeScript
• React
• Next.js
• NestJS
• Tailwind CSS
• Prisma
• PostgreSQL
• Socket.io
• Vite
• Canvas
• Claude Code

• Claude Code agent workflow design — boilerplate with agent rule sets and permission policies, plus a 5-phase pipeline (Spec-driven brainstorming → Plan + AI assets → Parallel subagent dev → Review/validate → PR release)
• Game boilerplate — one-liner init.sh to scaffold new games, solo/multiplayer mode support
• Game platform architecture — iframe + postMessage protocol-based game integration
• Kaboom (real-time minesweeper) — Socket.io multiplayer, matchmaking queue, ranking system
• Handeul (Korean Wordle) — solo game, daily puzzle generation, share feature
• Mythology Defense (solo · roguelike tower defense) — 15 augments (blessings), 5 special abilities on fused towers, 3 challenge modes, tile-based map with elemental type matchups (5 maps · 25 monster types), damage stats on result screen
• Mythology Defense · engineering — Canvas-based real-time rendering; at 1x/2x/4x speed modes, the per-frame delta time grows large enough that projectiles and enemies can skip over collision/path checks, so the loop splits the delta time into smaller sub-steps and runs update() multiple times per frame; seed-based deterministic PRNG to keep fusion/growth randomness fair; iframe postMessage platform bridge with standalone fallback

Developing the frontend for a global B2B/B2C cross-border e-commerce platform using Next.js. Built the full B2B transaction lifecycle (quotations, requests, proposals), supply/settlement/purchase management, real-time 1:1 chat, integrated search pages, community features, and SEO infrastructure.

• TypeScript
• Next.js
• React
• Tailwind CSS
• Zustand
• React Query
• React Hook Form
• Zod
• Tiptap
• STOMP
• MSW
• Storybook
• Vite
• i18n

• B2B transaction management — quotation create/edit/PDF preview/Excel download, request & proposal CRUD with detail pages (buyer/supplier dual-view)
• Unified product · supplier search results page — tab switching, SSR with sort/pagination synced to URL, improved type consistency
• Real-time 1:1 chat client over STOMP — REST + WebSocket hybrid architecture, migration to a WS-scoped token, action buttons branched by member type, transaction status event handling, file upload error recovery
• Storybook builder migration (webpack → Vite) — average cold build 28.9s → 13.9s (~2.08× faster), output size -23.5%, improved component DX and CI time
• Text editor replacement (Plate.js → Tiptap v2) — the originally web-oriented editor caused input and layout issues on mobile, so it was rewritten on Tiptap v2 (proven mobile compatibility)
• Supply · settlement · purchase history management — list + detail + filters, responsive tables, Excel/PDF download, memo feature
• Talk Round (community) — posts, comments, QnA, report/delete modals, API spec alignment, SSR/CSR integration
• SEO infrastructure — metadata, robots, sitemap, manifest, JSON-LD, OG, hreflang for 18 public pages, AI bot policy, 301 redirects, custom 404, OG/favicon/PWA icon assets
• Shared UI · i18n (ko/en/zh) · responsive design system — AlertDialog/ConfirmDialog, filter system, mobile-through-desktop responsive tables and forms, hreflang and i18n routing

Developed key groupware SaaS domains (attendance, approval, HR) on the frontend and owned the chat desktop app end-to-end. Analyzed recurring workflow friction and improved it through features.

• TypeScript
• React
• Tailwind CSS
• Zustand
• Socket.io
• Electron
• JWT
• Storybook
• Cypress
• Node.js
• Express

• Chat room creation time reduced from 6s to 0.1s — identified repeated request pattern as bottleneck and simplified the structure
• Auto-save for electronic approval drafts — prevented content loss from session expiry, balanced save frequency and server load with debounce/throttle, last-saved timestamp display
• Electron IPC socket optimization (88.8% fewer registrations) — resolved duplicate subscriptions (134→15) with Zustand + EventBus, eliminated typing delay
• Claude Code team workflow setup — standardized role-specific commands/context and code/commit/PR processes, ~56% team productivity gain (WBS basis)
• Playwright E2E testing · GitHub Actions CI/CD · AWS S3/CloudFront auto-deploy pipeline
• Code splitting — chunks 3,900KB→2,000KB, Lighthouse Performance 63→73, FCP 3.1s→2.2s
• Security — refresh-token migrated to http-only cookie, React Query cache reset

Solely designed and implemented the entire frontend for an AI image processing SaaS as a 2-person team with one designer. Drove the full product lifecycle from planning to production, launching 5 AI services live.

• React
• CSS Modules
• REST API
• Google Analytics
• AdSense

• Implemented full frontend for 5 AI image processing services solo
• Built user authentication & credit-based payment system
• Integrated National Police Agency missing persons OpenAPI
• Responsive design (mobile/tablet/desktop)
• Google Analytics & AdSense integration and operations

An LLM-powered developer personality assessment service built at a Wanted-hosted hackathon. Fine-tuned an LLM for developer type classification and designed the entire frontend.

• TypeScript
• React
• Python
• LLM Fine-tuning
• Java
• Spring Boot
• Docker

• Wanted Hackathon participant — planned and built a developer personality assessment service as a team
• LLM fine-tuning — customized model for developer type classification with prompt engineering
• Built entire frontend — assessment flow UI, result pages, and type-specific visualizations
• Deployment setup with Docker

Cohort 8 · Web Development Track

Intensive training in algorithms, frontend, and backend development. Completed 3 full-cycle team projects (6 members each), building strong collaboration and project delivery skills.

• Completed 3 team projects (6 members each) — planning, design, development, and presentation
• Established structured collaboration using Notion, API specs, and Figma documentation
• Improved development efficiency by transitioning from verbal to documentation-based communication