Yurii

Yurii Kovalchuk
ReactJs/Front-end Developer

Khmelnytskyi, Ukraine
[open contact info](look above in the "contact info" section) · [open contact info](look above in the "contact info" section)

Linkedin, GitHub

Profile
Skills
Professional Summary
Javascript ES5,ES6
Frontend Software Engineer with 10+ years of experience building
ReactJS, Next.JS, Redux,
high-performance, user-centric web applications. Expert in JavaScript (ES6+),
Redux-toolkit,
React.js, and modern frontend tooling with a strong background in scalable
React-Dom-Router,
architecture and UI/UX optimization. Proven track record of delivering complex
Styled-components
projects, improving platform performance by up to 40%, and leading teams in
TypeScript implementing cutting-edge React-based solutions. Passionate about clean code,
PWA component-driven development, and creating seamless user experiences.

Material UI React Core Skills
Framework • Languages & Frameworks: JavaScript (ES6+), TypeScript, React.js, Redux,
BootStrap Grid or Flexbox Next.JS, Redux Toolkit, React Native, PWA, Next.js
responsive • Styling & UI: Styled-components, Material UI, CSS3/SCSS/LESS, Tailwind,
Flexbox/Grid, Responsive Design
PostCSS, Tailwind, SCSS,
• Architecture & Tools: Webpack, Babel, Gulp, Jest, Storybook, GraphQL,
LESS, STYL etc.
REST APIs, Git, Azure DevOps CI/CD
React Native • Other: Performance Optimization, Code Reviews, Cross-Browser
Gulp/Webpack Debugging, UX Enhancements, Figma/Adobe XD

HTML/CSS
Employment History
Languages Senior Software Engineer, EPAM Systems
Ukrainian September 2023 — Present

Russian Headless Migration & React-PWA Development

• Migration from Magento to headless React-PWA architecture, improving
English load times by 35% and scalability across multiple regions.
(upper-intermediate) • Integrated GraphQL and Adyen payment system, reducing server response
times and enhancing checkout UX.
• Implemented advanced performance techniques (code splitting, lazy
loading, asset optimization) reducing initial load by 30%.
• Developed reusable UI components and enhanced UX using modern CSS
(Flexbox/Grid) and animations.
• collaboration with backend and DevOps teams to streamline API integration
and deployment workflows.
• Ensured code quality via thorough reviews, ESLint, JSdoc, Prettier, and Jest
unit testing.
eCommerce Redesign & Content Management Optimization

• Designed a “storybook-style” CMS constructor using Storybook.js, reducing
content creation time for managers by 50%.
• Created dynamic, reusable UI components based on Atomic Design
principles with integrated animations.
• Built a custom HTML5 video player for seamless background playback and
improved engagement.

ReactJs Developer, Bachoo Studio
February 2023 — Present

• Developed and integrated new UI features for an existing platform, adhering
to strict UI/UX guidelines.
• Delivered a 20% increase in user engagement by enhancing navigation and
visual consistency.
• Collaborated with cross-functional teams using React Hooks, Context API,
TypeScript, and Storybook.
• Maintained high code quality with rigorous unit testing (Jest/Enzyme).

ReactJs Developer , eye4TALENT, Copenhagen
November 2018 — December 2022

Develop and improve high loaded web platform for football players, scouts,
coaches etc.
Tech was using: ReactJs (hooks, context, useCallback etc.), Redux, Typescript,
ES5/ES6, Styled-components, Axios, Azure cloud storage, React-Dom-Router,
ServiceWorkers, PWA, SPA, CI/CD on AzureDevOps platform.

• Developed and optimized a high-load platform for football players and
scouts with React, TypeScript, and PWA.
• Increased platform stability and responsiveness by implementing service
workers and performance profiling.
• Independently handled UI/UX design and implementation, improving
overall usability and retention rates.
• Led integration with Azure Cloud Storage and optimized CI/CD pipelines on
Azure DevOps.

Front-end Developer , CoreValue, Khmelnitsky
July 2017 — November 2018

Develop and testing high-loaded CRM’s systems. Work with next technologies:
ReactJS, React Native, Redux, Jest(Enzyme), Material UI React, Angular JS (ng
- ver 1.X), JSdoc. At one of project I have great experience to develop custom
CRM dashboard with drag-n-drop elements(tables, charts, etc.). Also, I have a
great experience with improving performance at React Native, cause it has huge
problems with frames drops, and I successfully fix it.

Responsibility:

• Develop web applications use newest technologies and practice - ReactJS,
Redux, React Native, Axios.
• Unit testing with enzyme(jest).
• Work with CVS – GIT.
• Application performance improvements.
Front-end Developer , Avivi, Khmelnitsky
June 2016 — July 2017

• Develop websites using latest technology’s and trend’s in web-developing –
HTML5(canvas/video etc.), CSS3(flexbox, animation)
• Front-end team leader
• Using Bootstrap 4 grid to develop responsive web pages
• Create and use own task-manager builds in GULP to accelerate develop
process
• Develop PSD(sketch) to HTML/CSS/JS pixel by pixel and guarantee work in all
2 last versions of browsers
• Work with CVS – GIT
• Work with vue.js
• Develop web-applications with strong css3 animation and JS page routing

Front-end Developer , Web-systems.solutions , Khmelnitsky
December 2015 — June 2016

• Develop websites using latest technology’s and trend’s in web-developing –
HTML5(canvas/video etc.), CSS3(flexbox, animation)
• AngularJS with restAPI
• Create and use own task-manager builds in GULP to accelerate develop
process
• Develop PSD to HTML/CSS/JS pixel by pixel and guarantee work in all 2 last
versions of browsers
• Perform browser testing and debugging

Front-end Developer , RexSoft, Khmelnitsky
June 2015 — December 2015

• Develop websites using latest technology’s and trend’s in web-developing –
HTML5(canvas/video etc.), CSS3(flexbox, animation)/JS animation
• Using Bootstrap 3 grid to develop responsive web pages
• Work with Framework 7 to develop mobile web app
• Work with Backbone
• Avocode

Education
Bachelor's Degree in Computer Science , Lviv Polytechnic National
University , Lviv
September 2009 — June 2013

References
References available upon request