Igor Kirey, Developer in Kiev, Ukraine
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Igor Kirey

Verified Expert  in Engineering

JavaScript Developer

Kiev, Ukraine
Toptal Member Since
March 20, 2015

Igor is a skilled full-stack developer with experience in website development, creating APIs for mobile applications, large platforms with big data, and browser extensions. He is certified by AWS and has architecting and maintenance experience. Igor is comfortable working with different social and payment APIs and various frameworks. Igor is a highly self-managed person and team player with good communication skills, used to working in international teams.


Try Great Design Limited
React, HTML, JavaScript, CSS, Front-end, CSS Animations, Redux, Webpack...
React, TypeScript, Webpack, Storybook, Redux
Vesta Software LLC
AWS Lambda, Amazon Web Services (AWS), TypeScript, Amazon DynamoDB...




Preferred Environment

Amazon Web Services (AWS), React, Node.js, Agile, TypeScript

The most amazing...

...thing I've developed is a unique web application that gathers all internal data related to students, teachers, and education at Colorado University.

Work Experience

Front-end Developer (via Toptal)

2024 - 2024
Try Great Design Limited
  • Implemented a web app based on React, Redux, and TypeScript with wireframes in Figma.
  • Integrated responsive templates for desktop and mobile devices.
  • Implemented a feature for hybrid scrolling, carousel slider, and parallax effects.
  • Configured and optimized the production bundle using webpack and Babel.
Technologies: React, HTML, JavaScript, CSS, Front-end, CSS Animations, Redux, Webpack, TypeScript, Vercel

Team Lead and Developer

2023 - 2024
  • Implemented the main user-facing app based on React, Redux, and TypeScript.
  • Configured a project and optimized the build using Webpack and Babel.
  • Added Storybook, screenshot testing, and CI/CD pipeline.
  • Implemented a special plugin with custom linter rules.
Technologies: React, TypeScript, Webpack, Storybook, Redux

Team Lead and Back-end Developer

2022 - 2023
Vesta Software LLC
  • Used the AWS Cloud Development Kit (CDK) to create the whole infrastructure. Added required Amazon Cognito, AWS Lambda, Amazon DynamoDB, and Amazon S3 resources and settings.
  • Implemented new AWS Lambda functions for managing user's content and handling required business logic. I also created unit tests.
  • Reviewed client's requirements, helped organize the work process, and performed part of the project management work.
Technologies: AWS Lambda, Amazon Web Services (AWS), TypeScript, Amazon DynamoDB, Amazon Connect, JavaScript, React, Node.js, APIs, Jest, Agile, Front-end, Back-end, Amazon API Gateway, API Integration, Redux, Full-stack, Continuous Integration (CI), Continuous Delivery (CD), Continuous Deployment, WebStorm, Webpack, JSON Web Tokens (JWT), REST, Object-oriented Programming (OOP), Sass, Serverless, NPM, Yarn, SCSS, Amazon S3 (AWS S3), Amazon EC2, Architecture, Amazon Cognito, Docker, Asana, CI/CD Pipelines, Redux Toolkit, API Gateways, Amazon Simple Notification Service (Amazon SNS), Test-driven Development (TDD)

Front-end Developer

2022 - 2022
Illustria, Inc
  • Refactored most of the code, improved the structure, optimized components, and increased the performance and UX.
  • Moved the existing codebase to the latest React version and wrote unit tests.
  • Maintained the app, added more features, and worked on a responsive version.
Technologies: React, HTML, JavaScript, CSS, TypeScript, Sentry, APIs, Jest, API Integration, Storybook, Front-end, Continuous Integration (CI), Continuous Delivery (CD), Continuous Deployment, WebStorm, Stripe API, Webpack, Google API, Figma, NPM, Yarn, SCSS, User Experience (UX), CI/CD Pipelines, Google Analytics, Socket.IO, Test-driven Development (TDD)

Full-stack Developer

2021 - 2022
Sports Card Investor
  • Expanded and evolved analytics platform. Added new features, including screens, interactions, and workflows, improved the existing ones (e.g., for managing client's content), resolved bugs, etc.
  • Implemented new API endpoints for the main web platform and more endpoints for the mobile app (Node.js).
  • Implemented new AWS Lambda functions (serverless), background jobs processing external data and populating the database.
Technologies: JavaScript, React, Node.js, Serverless, PostgreSQL, Next.js, Scrum, Agile, Full-stack, AWS Lambda, Amazon EC2, Amazon Simple Queue Service (SQS), Amazon S3 (AWS S3), Amazon Web Services (AWS), SCSS, Yarn, NPM, WebStorm, TypeScript, Axios, Asana, JSON Web Tokens (JWT), REST, HTML, CSS, CSS3, HTML5, MongoDB, GitHub, REST APIs, Express.js, Less, Sentry, Google Analytics, Continuous Integration (CI), Continuous Delivery (CD), Continuous Deployment, JSX, Single-page Applications (SPA), SQL, Heroku, Back-end, APIs, Jest, API Integration, Redux, Front-end, Webpack, SOAP, Google API, Elasticsearch, Sass, User Experience (UX), Docker, CI/CD Pipelines, Redux Toolkit, API Gateways, Socket.IO, MySQL, Amazon RDS, Test-driven Development (TDD)

Full-stack Developer

2021 - 2021
SciMar One, LLC
  • Implemented a common user-facing application from scratch based on provided Figma designs, including responsive desktop and mobile templates.
  • Developed a back-office application from scratch based on my design to manage all user content and provide analytics and statistics.
  • Created back-end applications to handle authorization for the whole platform and using external Azure Functions.
Technologies: React, Front-end, Dashboards, Data Visualization, JavaScript, Azure, User Interface (UI), User Experience (UX), Node.js

Front-end Developer

2021 - 2021
Lantern Finance
  • Added new and refactored old website pages and responsive styles for mobile and desktop devices (React).
  • Migrated React to Next.js completely and deployed to the Firebase (hosting and functions).
  • Integrated Stripe into the main payment flow (subscription plans and checkout). Implemented new auth flow using Firebase API (registration, login, restore password, confirm email).
Technologies: React, Stripe API, Next.js, Front-end, Stripe, Full-stack, SCSS, Yarn, NPM, WebStorm, Axios, Firebase, Single-page Applications (SPA), HTML, CSS, JavaScript, CSS3, HTML5, GitHub, Google Analytics, Figma, JSX, APIs, API Integration, Webpack, REST, Google API, User Experience (UX)

Front-end Developer

2019 - 2021
  • Implemented new responsive templates based on provided designs using modern React features, HTML5, and CSS3.
  • Created a convenient complex dashboard that helps clients manage their personal data easily.
  • Developed a special reusable component for scrolling content with slides.
  • Built a Chrome extension for quick access to the platform's features and content. While browsing, regular users can see interesting and helpful information without opening the main app.
Technologies: CSS3, HTML5, React, JavaScript, Stripe API, Front-end, Chrome Extensions, Stripe, SCSS, NPM, Axios, HTML, CSS, GitHub, JSX, Single-page Applications (SPA), Search Engine Optimization (SEO), Heroku, APIs, API Integration, Webpack, JSON Web Tokens (JWT), REST, User Experience (UX), Sentry, Google Analytics

Full-stack Developer

2016 - 2019
University of Colorado Boulder
  • Created a complex application for collecting and representing analytics based on React and Node.js frameworks.
  • Implemented a custom menu component, which looks like a subway map (using the D3.js library). Each item in the menu was represented as a station. Integrated a special tool in the admin portal to manage the content of that menu.
  • Implemented logic for real-time user notifications based on web sockets. Integrated Tableau service.
  • Created HTML5/CSS3 templates with the mockups provided. Built a website for a hackathon event (using WordPress) and made all templates mobile-friendly.
  • Implemented user onboarding walkthrough feature (tutorial), which explains how to use the app step by step. Created an admin portal completely using my designs.
Technologies: WordPress, CSS3, HTML5, Socket.IO, D3.js, Webpack, Node.js, RefluxJS, React, JavaScript, Front-end, Agile, Full-stack, SCSS, NPM, Axios, Asana, Object-oriented Programming (OOP), HTML, CSS, MongoDB, Tableau, Redux, REST APIs, Express.js, JSX, Single-page Applications (SPA), API Integration, User Experience (UX), Redux Toolkit, Jira, Bitbucket

Full-stack Developer

2016 - 2017
ZooSale LLC
  • Developed a fully custom JavaScript framework for both front-end and back-office functionalities. Integrated a live messaging system for customers utilizing WebSockets technology.
  • Implemented back-end REST API based on Node.js. Used various services, including MongoDB for handling data, Redis for caching, and RabbitMQ for incoming tasks such as content addition and image uploads.
  • Implemented workers for making backups, optimizing images, and collecting statistics. Added CI/CD.
Technologies: Node.js, JavaScript, MongoDB, Redis, RabbitMQ

Back-end Developer

2016 - 2016
  • Extended the functionality of existing APIs and refactored and improved performance.
  • Implemented new user interface (UI) components. Worked on responsiveness and enhancing the user experience (UX).
  • Improved the app's structure and development process.
  • Fixed found bugs and helped the team to release the app successfully.
Technologies: CSS, HTML, JavaScript, RethinkDB, Node.js, NPM, Asana, REST, MySQL, Express.js, SQL, Back-end, Docker

Back-end Developer

2016 - 2016
  • Set up the infrastructure in AWS. Implemented new APIs and microservices.
  • Implemented new features for the client's platform, addressing debugging and improving performance.
  • Created shell scripts for managing logs and backups. Set up the environment using Kubernetes.
Technologies: Amazon Web Services (AWS), Docker, Node.js, MongoDB, NPM, Asana, REST, JavaScript, MySQL, GitHub, REST APIs, Express.js, SQL, Back-end, API Integration, Serverless, API Gateways, SOAP, Amazon RDS

Front-end Developer

2016 - 2016
Notum, Ltd.
  • Expanded and evolved the app and added new features, including screens, interactions, and workflows.
  • Created HTML5/CSS3 templates provided by the client. Worked on responsiveness and improving UX.
  • Worked on the back end, bug fixing, and optimization.
Technologies: Amazon Web Services (AWS), MongoDB, CSS, HTML, Meteor, React, Front-end, SCSS, NPM, JavaScript, CSS3, JSX, Single-page Applications (SPA)

Full-stack Developer

2015 - 2016
  • Worked on the infrastructure in AWS. Set up the CI/CD process.
  • Created complex HTML5/CSS3 templates with the mockups provided. Implemented UI components for the main application and back-office.
  • Created new API methods, wrote unit tests, and prepared documentation.
Technologies: RefluxJS, GitHub, Amazon Web Services (AWS), CSS, HTML, Node.js, React, JavaScript, Front-end, Full-stack, SCSS, NPM, Axios, Asana, REST, Socket.IO, HTML5, Redux, REST APIs, Less, Continuous Integration (CI), Continuous Delivery (CD), Continuous Deployment, JSX, Single-page Applications (SPA), APIs, API Integration, User Experience (UX), CI/CD Pipelines, Redux Toolkit, API Gateways, MongoDB, Jest, Test-driven Development (TDD)

Full-stack Developer

2015 - 2015
  • Implemented a new design for the company's website alongside the CTO and a designer.
  • Built lightweight and responsive templates using HTML5 and CSS3.
  • Implemented new APIs to fit the client's requirements. Maintained the legacy code and refactored old features.
Technologies: Meteor, Single-page Applications (SPA), APIs, Front-end

Back-end Developer

2013 - 2014
  • Created APIs for mobile applications, iOS and Android. Worked with AWS, including EC2, SNS, and SQS.
  • Wrote integration and unit tests. Improved the internal web app framework of the company.
  • Worked with Google, Facebook, and Twilio APIs to extend existing functionalities.
Technologies: CSS, HTML, Redis, MongoDB, Node.js, PHP, Scrum, Agile, Full-stack, AWS Lambda, Amazon EC2, Amazon Simple Queue Service (SQS), Amazon S3 (AWS S3), Amazon Web Services (AWS), NPM, Twitter API, REST, Object-oriented Programming (OOP), Twilio, JavaScript, CSS3, HTML5, MySQL, REST APIs, Twilio API, SQL, Amazon API Gateway, Back-end, APIs, API Integration, Amazon DynamoDB, Front-end, Sass, Amazon Simple Notification Service (Amazon SNS), Amazon RDS

Full-stack Developer

2012 - 2013
  • Created the corporate sites, stores, and portfolios. Wrote modules for CMS systems.
  • Worked with the internal frameworks of the company. Improved the internal CRM and company website.
  • Worked with different APIs, e.g., Google, Facebook, and Twitter, to implement new features or extend existing features.
Technologies: CSS, HTML, JavaScript, MySQL, PHP, Front-end, Scrum, Full-stack, Memcached, Object-oriented Programming (OOP), CSS3, HTML5, jQuery, WordPress, Web Design, SQL, Search Engine Optimization (SEO), Back-end

Full-stack Developer

2008 - 2012
Freelance Clients
  • Created corporate sites, stores, portfolios, and landing pages. Designed sites and different UI components.
  • Developed with different social and payment APIs to implement new or improve existing features.
  • Worked with different CMSs, including WordPress, OpenCart, and LiveStreet. Also used different self-made frameworks like Zend, CodeIgniter, etc.
Technologies: CSS, HTML, JavaScript, MySQL, PHP, Front-end, Full-stack, Memcached, Object-oriented Programming (OOP), Socket.IO, Redis, CSS3, HTML5, jQuery, WordPress, Elasticsearch, Web Design, SQL, Search Engine Optimization (SEO), Back-end


React-based application for a consulting company. I built the app from scratch using Redux and TypeScript as the front-end developer. The main goal was to implement a hybrid scrolling content feature, carousel slider, and parallax. I took wireframes from Figma and implemented fully responsive templates.

Grandma's Cookies

I was involved in a real estate and property management software project. In my role as a back-end developer, I crafted intricate APIs to support both client-side and back-office applications. Additionally, I established the necessary infrastructure in AWS, configuring resources and permissions. As a front-end engineer, I contributed to organizing the code refactoring process.


It is a centralized platform to solve legal problems in all cases at all stages. As a front-end engineer, I've built the main application, back office, admin panel, and browser extension. After the MVP, I worked on improving performance and creating a responsive version tailored for mobile devices.

Lantern Seamless Insights

The project was built to streamline terabytes of trades and extract the ones never meant to be seen by the retail investor. As a front-end engineer, I've created one user-facing app from scratch and moved another app from React to Next.js.

Market Movers by Sports Card Investor

It is the largest sports card database with sales data from multiple marketplaces. As a full-stack engineer, I worked on the main platform, including refactoring and optimizing the code, introducing new features, enhancing performance, creating new APIs, and developing microservices to retrieve external data.
2006 - 2011

Master's Degree in Mining Engineering

The Kryvyi Rih National University - Kryvyi Rih, Ukraine

MAY 2022 - MAY 2025

AWS Certified Cloud Practitioner

Amazon Web Services


Socket.IO, React, Node.js, REST APIs, RefluxJS, D3.js, Google API, Twitter API, jQuery, Stripe API, Stripe, Twilio API


Webpack, Asana, GitHub, WebStorm, Figma, NPM, Amazon Simple Queue Service (SQS), Sentry, JSX, Amazon Connect, Amazon Cognito, Redux Toolkit, Amazon Simple Notification Service (Amazon SNS), Tableau, Google Analytics, Jira, Bitbucket, RabbitMQ


JSON Web Tokens (JWT), Express.js, Next.js, Yarn, Redux, Jest


Object-oriented Programming (OOP), REST, Agile, Scrum, Continuous Integration (CI), Continuous Delivery (CD), Continuous Deployment, Search Engine Optimization (SEO), Test-driven Development (TDD)


CSS, HTML, JavaScript, CSS3, HTML5, TypeScript, SCSS, PHP, Sass, Less, SQL


Amazon DynamoDB, MongoDB, Redis, MySQL, Memcached, Amazon S3 (AWS S3), RethinkDB, Elasticsearch, PostgreSQL


Amazon Web Services (AWS), Amazon EC2, AWS Lambda, Heroku, WordPress, Twilio, Docker, Meteor, Firebase, Azure, Vercel

Industry Expertise

Web Design


Single-page Applications (SPA), Axios, Full-stack, Front-end, SOAP, Serverless, API Integration, APIs, Back-end, Amazon API Gateway, User Experience (UX), API Gateways, CI/CD Pipelines, Amazon RDS, Architecture, Chrome Extensions, Storybook, Dashboards, Data Visualization, User Interface (UI), CSS Animations

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