"Frontend
Developer"
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https://www.linkedin.com/in/kainyryukainy.dev@gmail.comhttps://github.com/kainy21Current location: Seoul, S.Korea

VOL. VI (Since 2020) ... No. 2
SEOUL, MONDAY, 5 JANUARY 2026

background

/kaɪni/ :

A Frontend Developer who views technology as the essential means of translating business ideas into clear, engaging user experiences. My focus is crafting systems and interfaces that communicate efficiently, operate reliably, and contribute to clear outcomes. I see frontend development as the bridge between business strategy and the user.
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A way to ensure complex concepts are made simple, making valuable products genuinely straightforward to navigate. I take a thoughtful and disciplined approach to my work, prioritising clarity and steady progress over perfection. I enjoy collaborating with colleagues across various teams and am equally productive when working independently.

LATEST DEVELOPMENT

Portfolio with RAG

Using: Next.js, TypeScript, Tailwind CSS, Supabase, Vercel, OpenAI, PostHog

Samsung Securities - RAG back office system

Stabilization and UX Enhancement of an internal admin dashboard deployed within a secure intranet. Independently addressed critical stability issues and spearheaded the data visualization design, significantly boosting operational efficiency.

Pharma-bros - E-commerce Platform

Solely developed the Frontend/Backend from scratch for a commerce platform achieving $4M+ (₩50B+) in monthly revenue. Quickly delivered the revenue-generating MVP in 3 months and built complex Group-Buying Management Systems, fundamentally contributing to TIPS selection and platform growth.

Experience Chronicle

2025

  1. Back office for Global Investment Insights Translator

    Megazone Crop · contract

    Improved a CoreUI-based internal dashboard by resolving API stability issues, refining lifecycle logic, and enhancing UI/UX. Strengthened error handling and user interactions for more reliable and seamless user experiences.

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    - Resolved irregular API call issues by optimizing request triggers - Fixed token-related bugs and clarified login session behaviors for better user interaction - Improved dashboard UI/UX with clearer visual hierarchy and usability enhancements - Refactored React lifecycle usage for more predictable and efficient hook execution - Implemented centralised error handling with user-facing feedback - Enhanced user interactions for a more seamless and friendly experience
2024

  1. Pharmacist influencer-led Health supplement e-commerce platform (closed & opened - commerce)

    Pharmabros · hybrid

    Served as the sole frontend engineer for both customer and admin platforms, owning architecture, UI flows, and implementation end-to-end. Delivered the MVP in 3 months and supported its selection for the TIPS government startup program.

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    - Sole frontend developer responsible for both customer-facing and admin interfaces. - Led the frontend architecture design and project setup using React, Typescript, React Query, Recoil, and Styled-components. - Collaborated with a backend developers and a DBA to build a fully functional closed/open shopping mall and admin dashboard. - Developed core user flows: Home, search, Korean certified identity verification, social login (Kakao, Naver), product listing, detail pages, cart, checkout, order history, campagins, reviews, and Q&A. - Built the admin panel from Figma designs without a dedicated publisher, including: - User management, order/cancellation/refund workflows - CS ticket handling, revenue dashboards (Chart.js), group-buying schedule management - Dynamic interfaces for different user roles (influencer/master dashboard views) - Some pages built with responsive UI for mobile and desktop views. - Delivered the MVP in 3 months, leading to successful selection for the TIPS government startup program. - The initial 6-month contract was extended based on performance and trust; continued to develop additional features.
2022

  1. Fashion E-commerce Platform

    LF · Full-Time

    Developed and optimized LFmall’s hybrid web-view architecture, improving performance and navigation stability. Delivered features across multiple services, migrated global search systems, and collaborated with backend teams to automate campaign workflows.

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    LF is a leading South Korean fashion and lifestyle company, known for operating premium clothing brands and e-commerce platforms. - Developed new features and maintained the service. - Managed multiple web-view operations in trasitioning to a hybrid app. - Transitioned recoil global search-filter state to URL based handling. - Create global functions for hybrid app to use react navigation. - Improved WebView memory performance. - Enhanced overall service performance. - Reduce home page landing speed -Automated creation of campaigns collaborated with a backend developer which was manual development by promoter -Migrated search filter values to url parameters from contextAPI
2020

  1. A pioneering web-novel platform in Korea.

    Joara · Full-time

    Improved a 687K MAU web novel platform through SPA migration, component refactoring, and new feature development. Enhanced efficiency by automating manual operational processes and supporting Agile delivery cycles.

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    - Continuously improve MAU 687k web applications - Migrate PHP based web application to responsive SPA(React) to increase scalability - Refactoring components using hooks and context API - Develop a settlement service to increase efficiency; used to be done by hand (monthly used: 6K) - Co-operate closely with Product, Design and Backend Development(PHP) to spec, build, test and deploy new features. - Working with the team in an Agile(Kanban, Scrum) environment - Implementing good practices(airbnb style guide, pair programming, code review, etc..)