Wadiz

Frontend Developer · 2020.11 ~ 2026.08

Owned every area of the maker services — funding, store, and the maker page studio — and carried out a generational shift from legacy (JSP) to a modern stack (React, Vite, pnpm), from domestic to global, and from IDC to the cloud.

Tech Stack

ReactTypeScriptNext.js 16SCSSReduxTanstack-queryReact-hook-formi18nextMSWVitepnpmESLint 9StorybookVitestPlaywrightSentryJavaSpring BootSpring CloudMyBatisMySQLAWS(EKS)KubernetesHelmDockerGitHub Actions(OIDC)Claude CodeQdrantFastAPI

Engineering

Proposed and Introduced the FE Development Process

2021.07 ~ 2026.08

Established planning/design/API review, technology adoption review, development schedule estimation, and follow-up task management as a single development process and rolled it out to the team.
Proposed it directly to the team to make development schedule estimation practical and to catch missing items; it is now used as the standard for running projects.
Introduced Storybook, API interface sharing, and MSW so work could proceed in parallel with other departments, improving development speed and efficiency.
Continued follow-up work such as performance and web accessibility improvements even after development was complete, raising service quality and stability.

Role: Front-End Developer
Frontend: React, Scss, Redux, React-query, Storybook, Vitest, MSW, Playwright, Typescript
URL: FE development process article

Introduced MSW (Mocking Service) and Built a Mock Data System

2021.11 ~ 2026.08

Built an FE-only mock server with MSW so the frontend could carry out data integration and validation even before the BE APIs were finished.
Received API interfaces in advance during the development phase to define mock data, enabling parallel BE/FE development and early planning and design review.
Reused the same mock data across the mock server, Storybook, unit tests, and Playwright to lower maintenance cost.

Role: Front-End Developer
Frontend: React, Storybook, Vitest, Playwright, MSW
URL: MSW (mocking library) adoption article

Development Productivity Improvements

2022.01 ~ 2025.12

Upgraded packages (React v16.8 → v18.2) to make the latest ecosystem based on concurrent rendering available.
Migrated the build system from webpack (CRA) to Vite 6.0, improving dev server startup and build speed.
Switched from yarn classic to pnpm, resolving phantom dependency and storage space issues.
Applied FSD (Feature-Sliced Design) architecture to make layer boundaries explicit.

Role: Front-End Developer
Frontend: React, Vite, pnpm, FSD, Typescript
URL: CRA to Vite migration article

Development Standardization and Automation of Repetitive Work

2025.01 ~ 2026.07

Standardized ESLint 9 (flat config), Prettier, stylelint, and husky across the entire studio in one pass, eliminating code style debates.
Automated the commit convention as a skill, enforcing issue key and type formats.
Removed repetitive work with scheduled workflows — automatic merging of localization branches, automatic design token synchronization, stale branch cleanup, and regular release branch preparation.
Kept automated PR code review (Claude Code Action) resident in CI, shortening review lead time.

Role: Front-End Developer
Frontend: ESLint 9, Prettier, stylelint, husky, GitHub Actions, Claude Code

Service Stability Improvements (Test Automation · Observability)

2022.08 ~ 2026.08

Introduced Vitest unit/integration tests and Playwright E2E tests to quickly identify and respond to live issues that increased as the service expanded.
Wrote test code based on the QA team's verification scenarios and built the developer verification flow into an automation server.
Wired up GitHub Actions scheduled runs, live-environment run guards, and Slack notifications so failures are detected immediately.
Set up Storybook with MSW and react-query integrated, creating a development environment where screens can be verified without APIs.
Started with Cypress sanity tests, migrated to Playwright E2E, and built independent E2E workspaces per app.
Improved test robustness — replaced data-testid-dependent selectors with role queries and locale-agnostic label matchers, and changed immediate assertions to waitFor-based waits so tests do not break across languages and environments.
Improved type safety by removing ts-ignore, and added a check for the existence of i18n localization keys to prevent runtime errors caused by missing translation keys.
Operated Sentry-based frontend error monitoring, managing release attributes in code and separating attributes per environment.

Role: Front-End Developer
Frontend: Vitest, Playwright, Cypress, Storybook, MSW, Sentry, Typescript
URL: Playwright adoption article

Performance Optimization

2022.08 ~ 2025.06

Improved loading speed and CLS (Cumulative Layout Shift) through image lazy loading, preloading, and reflow prevention, and wrote about the process on the tech blog.
Converted gifs to mp4 and applied playback control based on viewport and iOS low power mode to cut media costs.
Improved the bundle splitting strategy with per-tab rendering optimization and design system chunk merging.

Role: Front-End Developer
Frontend: React, Vite, Web Performance, Core Web Vitals
URL: gif to mp4 conversion article

Built an AI Development Workflow (Claude Code-based Plugins · Skills · Harnesses)

2025.06 ~ 2026.07

Codified the entire development process into an executable pipeline (research → prd → develop → review → verify orchestrator).
Designed a cost-optimal order — five static analyses run in parallel up front, and the expensive E2E verification runs only when they pass.
meta-harness — built a meta loop that diagnoses and improves defects in the harness itself (docs, agents, hooks). It preserves signals as raw traces without summarization, fans out failure diagnosis in parallel, and enforces additive-first patches that do not regress what already exists, along with user approval gates.
product-spec — a 7-stage harness running from planning draft → PRD → adversarial validation → acceptance criteria (Given-When-Then) that validates planning quality before development begins.
Enforced deterministic guardrails as hooks — blocking dangerous commands, blocking creation of sensitive files, and automatic linting. Applied the branching principle that "anything requiring judgment is a rule, anything that must be obeyed is a hook."
Design-to-code automation — built a skill that automatically generates design system components and email templates from Figma.
In-house code RAG — composed of semantic + keyword hybrid search (combined with RRF), reranker re-ranking, structural chunking at the function/class level, Git diff-based incremental synchronization, and dual REST and MCP interfaces.

Role: Front-End Developer / AI Workflow Engineer
Frontend: Claude Code, MCP, FastMCP, Qdrant, FastAPI, Docker Compose
URL: Frontend harness engineering article

Maintenance and Incremental Modernization of the Legacy Monolith (Spring MVC + JSP)

2020.12 ~ 2026.07

Operated the SSR monolith without interruption for 5 years and 8 months, modernizing it incrementally in parallel with new projects.
Ran a hybrid structure that mounts React components inside JSP screens.
Owned the ongoing reflection of legal and policy revisions (including terms version management) for 5 years.
Completed the migration that handed URL mapping from the legacy system over to the new frontend/cloud, alongside JSON-LD-based SEO cleanup.

Role: Front-End Developer
Frontend: JSP, Spring MVC, React, Typescript, JSON-LD

Full-stack / DevOps Expansion

2024.01 ~ 2026.07

Developed Spring Boot backend APIs directly — tiered admin permissions and stored before/after snapshot audit logs to secure traceability.
Reduced the attack surface by removing risky APIs and consolidated account issuance into a single controlled procedure (handling security on both the "add features" and "remove risk" sides / ISMS compliance).
Migrated from the IDC environment to the AWS EKS cloud — injected common and per-service ConfigMaps separately with Spring Cloud Kubernetes Config.
Adjusted the Spring Cloud BOM to a compatible train to fit the Java 8 runtime constraint (a decision that prioritized stability over upgrading to the latest version).
Built a multi-environment deployment pipeline based on GitHub Actions OIDC, eliminating long-lived access keys.
Configured service environments with Helm charts and moved secrets out of code, externalizing them into environment variables.
Handled the cloud migration on the frontend side by externalizing host URLs into environment variables and reorganizing CORS.

Role: Full-Stack Developer
Backend: Java, Spring Boot, Spring Cloud, MyBatis, MySQL
DevOps: AWS EKS, Kubernetes, Helm, Docker, GitHub Actions(OIDC)

Built the Wadiz Store Detail Page from Scratch

2021.05 ~ 2021.08

Wadiz store detail page purchase process screen

The first large-scale ownership project taken end to end from a blank slate — component design, API integration, the payment flow, responsive and image optimization, and post-launch stabilization.
Developed the store detail page main UI and its tabs (story, satisfaction reviews, returns/exchanges).
Implemented the purchase process including product option selection and inventory quantity management.

Role: Front-End Developer
Frontend: React, Scss, Redux, Redux Toolkit, React-query, Storybook, Jest, MSW
URL: Wadiz Store launch news

Launched Wadiz Membership (Supporter Club)

2022.02 ~ 2022.05

Wadiz Supporter Club introduction screen

Owned the Supporter Club UI and the entire supporter side, which delivers a range of membership content and benefits within the Wadiz service.
Developed funding/store payments, the Supporter Club sign-up process, and Supporter Club event pages.

Role: Front-End Developer
Frontend: React, Scss, React-query, React-hook-form, Storybook, Jest, MSW
URL: Wadiz Membership (Supporter Club) introduction

3-Depth Product Sub-options and Reward Option Improvements

2022.07 ~ 2023.06

Wadiz funding product option improvement screen 1

Wadiz funding product option improvement screen 2

Extended the existing 1-depth sub-options to support up to 3 depths, and implemented adding, changing, and deleting single and set-composition products.
Revamped legacy features and designs such as products without options and direct input to the React and design system standard.
Revamped the reward selection, funding payment, and scheduled payment flows across three phases, P1 through P3.

Role: Front-End Developer
Frontend: React, Scss, React-query, Storybook, Jest, Playwright, MSW
URL: Wadiz product option improvement news

Operating the Funding/Store Maker Studio

2020.12 ~ 2026.08

Developed the Maker Studio features and UI required to create funding projects.
Continuously owned maintenance and operational issue response for the supporter (funding, store) and maker (studio) services.

Role: Front-End Developer
Frontend: React, Scss, React-query, Redux(Redux Toolkit), React-hook-form, Storybook, Vitest, Playwright, MSW, Typescript
URL: Reward Maker Studio revamp announcement

Product Work

Global Service Transition

2025 ~

Converted a domestic-only service into an i18next-based global multilingual service (Korean text extraction → AI translation → localization, with an automated translation synchronization pipeline in operation).
Built the global Maker Studio from scratch — global settings for exchange rate, currency, and country, reward design, settlement information/settlement history, maker information, and global 1:1 inquiries.

Pricing Plan Revamp and Maker Home (Dashboard) Revamp

2025

Completely revamped the maker pricing plan system and the maker home dashboard.

Built Commerce Operations Tools

2023 ~ 2024

Built a consignment shipping service (home, sales management, inbound requests) from scratch with support for bulk Excel registration.
Implemented bulk shipping management and bulk product price editing.
Implemented the new "open a store without funding" flow across the studio, admin, and supporter surfaces.

Built the Story Domain from Scratch

2025

Built the story domain from scratch, including story detail/home, story translation, and multilingual support.

Built Pre-order and Global/Encore Funding from Scratch

2021 ~ 2022

Built the pre-order service and the global/encore funding services from scratch.

Cloud Migration Support

2026

Handled the frontend cloud migration work, including domain switching and dynamic URL generation.