PhyongNam Kim, Developer in Seoul, South Korea
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PhyongNam Kim

Verified Expert  in Engineering

Full-stack Developer

Seoul, South Korea
Toptal Member Since
September 19, 2019

Kim is an accomplished front-end developer committed to building outstanding websites and mobile apps, with some back-end experience. With his expertise in React, React Native, Vue, and other technologies, he creates visually stunning, user-friendly, secure, and performant experiences. Kim's impressive track record includes developing large-scale projects from scratch, updating existing ones to ensure high quality, and enhancing them with new features and pages.


React, TypeScript, Gatsby, Storybook, SCSS, Tailwind CSS, React Testing Library...
Vue, Nuxt.js, Vuex, TypeScript, Storybook, GraphQL, SCSS, Bootstrap, Jest...
React Native, React, GraphQL, Material UI, Jest, Appium, Xcode, Android Studio...




Preferred Environment

Git, Visual Studio Code (VS Code), MacOS

The most amazing...

...thing I've coded is a collaboration app for remote teams, which has been adopted by renowned companies such as Alaska Airlines, Delta Air Lines, KFC, and more.

Work Experience

Senior React Front-end Developer

2021 - 2023
  • Developed React UI components for company-wide design systems ensuring consistency and enhancing the user experience.
  • Migrated legacy AngularJS 1.6 code to React 18 incrementally, converting pages individually and managing routing.
  • Made minor updates and fixes to the existing C# .NET back end.
  • Maintained legacy AngularJS 1.6 code and a WordPress website.
Technologies: React, TypeScript, Gatsby, Storybook, SCSS, Tailwind CSS, React Testing Library, Angular, WordPress, PHP, C#, .NET, CI/CD Pipelines, Unit Testing, Front-end Development, Full-stack Development

Senior Vue Front-end Developer

2019 - 2021
  • Developed a business insight news website and its accompanying dashboard, inspired by platforms like Bloomberg.
  • Built a website for an AI service using serverless architecture as part of a side project.
  • Developed email templates for the marketing team and integrated them with Mailchimp.
  • Implemented performance optimizations, improving website speed and enhancing user experience.
Technologies: Vue, Nuxt.js, Vuex, TypeScript, Storybook, GraphQL, SCSS, Bootstrap, Jest, Cypress, LaunchDarkly, Litmus, Mailchimp, Amazon Web Services (AWS), GitLab CI/CD, Unit Testing, E2E Testing, A/B Testing, Serverless Architecture, Front-end Development

Senior React/React Native Developer

2017 - 2019
  • Developed an iOS and Android app that helps remote teams coordinate and perform time-sensitive tasks quickly and efficiently.
  • Built a website and admin dashboard for scheduling, mission management, and notifications.
  • Integrated Azure Active Directory B2C (ADB2C) for SSO, utilized various Firebase features, and integrated APIs.
  • Worked in test-driven development (TDD), developing unit testing and end-to-end testing scripts and integrating them into a CI/CD pipeline implemented on a Jenkins server.
  • Worked in an agile and fast-paced environment, collaborating closely with team members and other functional teams.
Technologies: React Native, React, GraphQL, Material UI, Jest, Appium, Xcode, Android Studio, Socket.IO, Firebase, Azure Active Directory B2C (ADB2C), Jenkins, Fastlane, Unit Testing, E2E Testing, Test-driven Development (TDD), Front-end Development, Mobile App Development

Full-stack React, Node.js, and React Native Developer

2014 - 2017
  • Worked on developing real-time tracking, feedback systems, live chat, and a payment system for both the website and the admin dashboard.
  • Developed the MVP version of a fleet-based car-sharing iOS and Android app, which helped the company secure funding and expand.
  • Developed RESTful APIs for feedback systems and a WebSocket for live chat.
Technologies: React Native, React, Material UI, Node.js, Express.js, MongoDB, Xcode, Eclipse, WebSockets, REST APIs, Payment Gateways, Maps, Geolocation, IAP SDK, Full-stack Development, Mobile App Development, Minimum Viable Product (MVP)

Full-stack Developer

2012 - 2014
  • Worked on developing the UI/UX of the platform providing eCommerce and advertising services.
  • Developed a variety of charts and graphs on the admin dashboard, showcasing analytical insights into consumer behavior and trends.
  • Worked on developing APIs and a database for stock management and analysis.
Technologies: HTML, CSS, JavaScript, jQuery, D3.js, Node.js, PostgreSQL, RESTful Microservices, Full-stack Development

Junior Web Developer

2011 - 2012
  • Acquired valuable practical experience and deepened understanding of software engineering beyond what can be learned in a university setting.
  • Gained insights and real-world experience into project management methodologies, communication within a team, overall software development lifecycle, software architecture, etc.
  • Worked on internal company projects, including developing a dashboard, tracking tool, and internal news and blogging website.
Technologies: HTML, CSS, JavaScript, jQuery, PHP, MySQL

Component Library for a Design System
I worked as a senior front-end developer and developed components for the design system. This design system is used across various websites developed and utilized by the company. We focused a lot on supporting accessibility.

Mobile App to Manage and Track Remote Teams
An app that enables remote teams to coordinate and perform time-sensitive tasks quickly and efficiently, used by renowned enterprises such as KFC, Alaska Airlines, and Delta Air Lines.

I worked as a senior React Native developer in a mobile team, collaborating with both team members and cross-functional teams. I developed critical features, including single sign-on (SSO), offline-supported news bulletins, push notifications, live chat, and Beacon signal detection.

We utilized TDD to build a high-quality app.

Admin Dashboard for Remote Team Management and Tracking Platform
An admin dashboard for the platform is used to manage and track remote teams. I worked as a senior front-end developer on a dashboard project, focusing on developing the SSO and mission scheduling system.

This dashboard is for the Springshot platform, which is utilized by large companies such as KFC, Alaska Airlines, Delta Air Lines, and others.

Business Insight News Platform
A business insight news platform similar to Bloomberg. I was a senior Vue.js front-end developer, contributing to the news website and admin dashboard.

My responsibilities included optimizing performance, updating web pages to match new designs, adding new pages with A/B testing, developing email templates, etc.

MVP for a Fleet-based Car-sharing Mobile App

I worked on developing the MVP iOS and Android app for a fleet-based car-sharing platform. This app played a crucial role in helping the company secure funding and expand its operations.

The app is now one of the top car-sharing apps in Korea.

Website and Admin Dashboard for Fleet-based Car-sharing Platform
A website and admin dashboard for one of the top car-sharing platforms in Korea. I worked as a full-stack developer and developed the feedback system, payment system, and support system for both the website and admin dashboard.

Social Community and Membership Platform

A membership platform that empowers content creators to run subscription services by providing comprehensive business tools. I worked as a senior React developer and developed onboarding pages, a creator's dashboard, and some global UI components.

Website for Document Analyzing AI Service
A website with a membership that provides services to analyze documents using AI.

As the sole front-end developer in this project, I owned all front-end development tasks, from architecture design and language/framework selection to deployment and testing.
2007 - 2010

Bachelor's Degree in Computer Engineering

Ajou University - Suwon, Korea





Business English Certificate

Cambridge English




MARCH 2011 - MARCH 2014




React, Vue, Vuex, React Testing Library, REST APIs, Node.js, jQuery, Socket.IO, Stripe, D3.js


LaunchDarkly, Litmus, Mailchimp, Azure Active Directory B2C (ADB2C), Xcode, Android Studio, GitLab CI/CD, Jenkins, Fastlane


React Native, Next.js, Nuxt.js, Tailwind CSS, Material UI, Bootstrap, Redux, Jest, Cypress, Appium, Express.js, Angular, .NET


TypeScript, GraphQL, SCSS, Sass, HTML, CSS, JavaScript, PHP, C#


Unit Testing, E2E Testing, Test-driven Development (TDD), Serverless Architecture


GreenSock Animation Platform (GSAP), Firebase, Amazon Web Services (AWS), Eclipse, WordPress


PostgreSQL, MySQL, MongoDB


Gatsby, Storybook, Chakra UI, Front-end Development, Design Systems, A/B Testing, Mobile App Development, iOS App Development, Android App Development, Maps, Geolocation, IAP SDK, Minimum Viable Product (MVP), Payment Gateways, RESTful Microservices, WebSockets, CI/CD Pipelines, Full-stack Development, Web Accessibility

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