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Seungah Hong profile photo

Seungah Hong

Frontend Developer

A developer who grew from frontend into full-stack and AI workflow engineering — leading legacy modernization, global expansion, and cloud migration for a commerce platform.

Experience
15 years
Companies
4
Articles
69

For years I owned the entire maker service surface — funding, store, and maker studio — driving the generational shift from a legacy JSP stack to React, Vite, and pnpm, from a domestic service to a global one, and from IDC servers to the cloud.

I codified our development process itself into a Claude-based harness, raising the team's engineering and quality culture.

I stay curious about evolving technologies and keep learning continuously.

Because sharing matters, I publish consistently on my tech blog and Notion.

When something blocks development, I take it on and resolve it rather than work around it.

Tech Stack

Frontend

ReactTypeScriptNext.jsGatsbyReduxRedux ToolkitRecoilZustandJotaiSWRTanstack QueryReact Hook Formi18nextMSWTailwind CSSStyled-ComponentsSCSSCSS ModulesHTML5CSS3JavaScript

Build & Tooling

ViteWebpackesbuildpnpmFSD (Feature-Sliced Design)ESLint 9 (flat config)PrettierstylelinthuskyTree Shaking

Test

VitestJestPlaywrightCypressStorybook

DevOps & Infra

AWS (EKS, S3, SES, ECR)KubernetesHelmDockerGitHub ActionsOIDC deployment authQdrantFastAPI

AI Tooling

Claude CodeHarness engineeringRAG (hybrid search)MCPFastMCPFigma MCP

Monitoring

Sentry

Collaboration

GitJiraConfluenceSlackFigmaNotion

Contact

gmm117@naver.com
GitHub
Blog
Notion

Career

15 years of development experience across 4 companies. Select a company to open its detail page.

Wadiz logo

Wadiz

Frontend Developer

2020.11 ~ 2026.08

Covered the entire funding, store, and Maker Studio domain — built the store detail page and the global Maker Studio from scratch, drove the incremental React migration of the legacy JSP monolith, led the move to the AWS EKS cloud, and established a Claude Code-based AI development workflow.

Tech Stack

ReactTypeScriptNext.js 16SCSSReduxTanstack-queryReact-hook-formi18next

Highlights

+9 more

View details

Projects

Products I build and operate myself, plus talks and articles published externally.

Personal Projects

Personal Portfolio screenshot

Personal Portfolio

2022.11 ~

A hybrid two-tab architecture that switches between an SSR portfolio and a client-side AI chat. Built on Next.js 16 App Router, React 19, TypeScript 5, and Tailwind CSS 4, with a Groq (Llama 3.3 70B) streaming chatbot, keyword-detected data cards, ko/en localization, dark mode, and WAI-ARIA tabs.

Next.js 16React 19TypeScript 5Tailwind CSS 4Groq APINodemailer
Vercel
RepositoryVisit site
Tech Blog screenshot

Tech Blog

2022.11 ~

A Gatsby (SSG) tech blog with 69 articles written in both Korean and English — 138 documents in total — tracing a learning path from frontend frameworks through build tooling and testing to AI harnesses.

GatsbyTypeScriptStyled-ComponentsVitestPlaywright
gh-pages
RepositoryVisit site

Presentations & Articles

Wadiz Funding Detail Page Performance Optimization cover image

Wadiz Funding Detail Page Performance Optimization

2022.08

Image lazy loading, content reflow prevention, and broad image preloading improved load time and CLS; the work was published on the company tech blog.

Read more
Web Document Editing Method Patent cover image

Web Document Editing Method Patent

2020.01

A patent filing covering data and structure modeling for inter-module communication and the actor/updator/render architecture. (Search application no. 1020674990000)

Read more

Study Archive

Since 2020 I have published 69 technical articles in both Korean and English, totaling 138 documents. The 64 links below are grouped by topic — each major release, from React 17→18→19 to Next.js 13→14→15 and Vite 6→7→8, was verified hands-on and written up.

Browse the full blog

Frequently Asked Questions

The questions I get asked most about my career, skills, and how to reach me.

Who is Seungah Hong?

Seungah Hong is a frontend developer with 15 years of experience, currently building the funding, store, and maker studio services at Wadiz. Starting from frontend, the scope expanded into Spring Boot backend APIs, AWS EKS cloud migration, and Claude Code based AI development workflows.

How many years of experience and which companies?

15 years across 4 companies: Wadiz (Nov 2020 – present, frontend), Hancom (Dec 2016 – Nov 2020, WebHwp Canvas rendering), Osstem Implant (Apr 2013 – Dec 2016, Windows dental software), and Bluebird Soft (Jun 2010 – May 2012, embedded terminals).

What is the main tech stack?

React, TypeScript, and Next.js form the core. State management uses Redux Toolkit and Tanstack Query; testing uses Vitest, Playwright, Storybook, and MSW; builds run on Vite and pnpm. Backend work uses Java and Spring Boot, infrastructure uses AWS EKS, Kubernetes, and Helm, and AI tooling covers Claude Code, RAG, and MCP.

What was the role at Wadiz?

Ownership covered the entire maker service surface — funding, store, and maker studio. New builds included the store detail page and the global maker studio; the legacy JSP monolith ran for 5 years and 8 months while being incrementally migrated to React; and the IDC environment moved to AWS EKS. Details are at /career/wadiz.

How was test automation built?

It started with Cypress sanity tests, moved to Playwright E2E, and grew into per-app independent E2E workspaces. MSW mock data is shared across server mocking, Storybook, unit tests, and E2E, and data-testid selectors were replaced with role queries and locale-agnostic label matchers so tests survive multi-language and multi-environment runs.

How was the AI development workflow built?

The whole development cycle is codified as a research → prd → develop → review → verify orchestrator. Five static analyses run in parallel first, and expensive E2E verification runs only after they pass. Alongside it run meta-harness, which diagnoses and repairs the harness itself, and product-spec, which validates planning quality before implementation starts.

Any web performance optimization experience?

Yes. The Wadiz funding and pre-order detail pages were optimized and the work was published on the company tech blog in August 2022. Image lazy loading, content reflow prevention, and broad image preloading improved load time and CLS, and later work on gif-to-mp4 conversion and bundle splitting reduced media and bundle cost.

How is technical knowledge shared?

Since 2020, 69 articles have been published in both Korean and English, totaling 138 documents. 64 of them are organized by topic in this portfolio. Major releases — React 17→18→19, Next.js 13→14→15, Vite 6→7→8 — are verified hands-on and written up each time.

How can I get in touch?

Email gmm117@naver.com or use the contact form at the bottom of this page. Work is also visible on GitHub (https://github.com/seungahhong) and the tech blog (https://seungahhong.github.io/).

Contact

Feel free to reach out with an opportunity or a question.