Kostya Belenkii, Developer in Nahariyya, Israel
Kostya is available for hire
Hire Kostya

Kostya Belenkii

Verified Expert  in Engineering

Senior Front-end Developer

Nahariyya, Israel

Toptal member since June 18, 2020

Bio

Kostya is a senior front-end developer with nine years of experience, and he has developed web applications for more than a decade. As a highly skilled web engineer and consultant, he has led teams to deliver complex projects in diverse agile environments. Kostya blends his scientific background with his passion for building and enhancing products that have a positive impact on people.

Portfolio

Covver tech Ltd
TypeScript, React, Storybook, Next.js, Vercel, FullStory, Sentry, A/B Testing...
Airmeet
Agile Software Development, Firebase Web SDK, React, TypeScript...
500Tech
Git, Jest, Jira, GraphQL, Webpack, CSS, Redux, React, TypeScript, JavaScript...

Experience

  • HTML - 12 years
  • Agile Software Development - 11 years
  • JavaScript - 10 years
  • CSS - 10 years
  • React - 8 years
  • Unit Testing - 6 years
  • TypeScript - 4 years
  • Next.js - 2 years

Availability

Part-time

Preferred Environment

Google Drive, Slack, Trello, Terminal, Visual Studio Code (VS Code), MacOS, Git

The most amazing...

...project I've completed was the front end of a SaaS system for cybersecurity analysts where I built and led a distributed team in a startup environment.

Work Experience

Leading Front-end Developer

2021 - PRESENT
Covver tech Ltd
  • Architected reusable UI component library infrastructure, including automated visual regression testing.
  • Developed multiple rich single-page apps from scratch in close connection with the product team. Led a team of front-end developers to bootstrap the initial version.
  • Set up client-side monitoring (both product and technical) and A/B testing infrastructure.
Technologies: TypeScript, React, Storybook, Next.js, Vercel, FullStory, Sentry, A/B Testing, UI Animation, User Interface (UI)

Principal Web Developer

2020 - 2021
Airmeet
  • Led a front-end team to develop one of the biggest modules, a contextual sidebar containing an event feed, messaging, notifications, and user and access management features.
  • Took part in front-end performance analysis and optimization and solving the app scaling problems.
  • Coached the team to execute Agile development processes and to use the Clubhouse project management tool efficiently.
Technologies: Agile Software Development, Firebase Web SDK, React, TypeScript, Styled-components, Storybook, Clubhouse, HTML, JavaScript, CSS, Git, Redux, Node.js, Firebase, GitHub, Styled System, Team Leadership, Front-end, User Interface (UI)

Senior Front-end Developer

2017 - 2020
500Tech
  • Developed several diverse projects from scratch, using JavaScript and React. I played different roles in each project, ranging from a one-month contract developer to the lead developer for a large-scale project.
  • Participated in many projects as a senior developer, handling project planning, infrastructure, technical design, and team mentoring.
  • Contributed to large enterprise and startup projects, using GraphQL, React Native, and TypeScript.
  • Delivered presentations on React/Redux internally and at local meetup groups.
Technologies: Git, Jest, Jira, GraphQL, Webpack, CSS, Redux, React, TypeScript, JavaScript, HTML, Agile Software Development, Amazon Web Services (AWS), Node.js, React Native, AWS Amplify, Functional Programming, GitHub, Styled-components, SaaS, Team Leadership, REST APIs, Front-end, User Interface (UI)

Front-end Team Leader

2015 - 2017
CyberInt
  • Built and led a team of five remote developers to build a rich, single page application from scratch within a very tight deadline. We maintained this application for two years with a tested and highly reusable codebase.
  • Participated in an R&D process optimization and helped others improve their organizational skills.
  • Led open source initiatives in the company by publishing packages on npm and GitHub.
  • Took part in organizing and speaking at a local React/Redux meetup group.
Technologies: Jira, Git, Enzyme, CSS, Webpack, Redux, React, JavaScript, HTML, Agile Software Development, GitHub, SaaS, Cybersecurity, Team Leadership, REST APIs, Front-end, User Interface (UI)

Front-end Web Developer

2014 - 2015
Magora Systems
  • Improved and maintained a rich web route-planning application using vanilla JS and SVG.
  • Developed a midsize web application from scratch using AngularJS.
  • Improved performance of an SVG-based timeline module, enabling the ability to increase the number of supported elements by more than 10x.
Technologies: Sass, AngularJS, JavaScript, HTML, CSS, Git, Agile Software Development, Front-end, User Interface (UI)

Full-stack Web Developer

2010 - 2013
Code Your Dream
  • Implemented and maintained a web platform that allowed users to create, share, and collaborate on slide presentations.
  • Deployed and maintained a personality test platform that included the ability to create questionnaires based on the mathematical formulas that analyzed user responses.
  • Participated in many diverse full-stack projects, contributing to all technical stages, from requirements analysis to deployment.
Technologies: Sass, JavaScript, Drupal, PHP, HTML, CSS, Git, Agile Software Development, Linux

Lumigo

https://lumigo.io/product/
Lumigo is a monitoring and debugging app for serverless applications, built with TypeScript, React, and Redux. As a lead front-end developer, I established and led many parts of the project including infrastructure improvements, unit testing, styling, code conventions, building commonly used components, and mentoring other developers.

Platform for Cybersecurity Analysts

https://blog.cyberint.com/introducing-argos-2.0
This SaaS system for cybersecurity analysts includes live feeds, dashboards, and a wide variety of diagrams, forms, and communication tools. I built a team of front-end developers, established a remote workflow, and developed the project in an agile manner within a startup environment.

We used React, Redux, and functional programming approaches, allowing us to reuse code pretty easily. This, in turn, allowed us to build a flexible, scalable, and maintainable UI for data analysts that supports a large number of tabs inside the application to hold all the necessary information in one place.

One of our biggest successes was shipping the first release very quickly as a result of hiring a distributed freelance team and using a straight development process.

Platform to Host Virtual Conferences

https://www.airmeet.com/
A React, single-page application to host virtual events, such as meetups, conferences, and summits. I led a front-end team to develop one of the biggest modules, a contextual sidebar containing an event feed, messaging, notifications, and user and access management features. I also took part in front-end performance analysis and optimization, solved the app scaling problems, and coached the team to execute Agile development processes efficiently.
2010 - 2011

Master's Degree in Computer Science

Novosibirsk State University - Novosibirsk, Russia

2005 - 2009

Bachelor's Degree in Computer Science

Novosibirsk State University - Novosibirsk, Russia

Libraries/APIs

React, REST APIs, AWS Amplify, Node.js, Ramda, Firebase Web SDK

Tools

Git, Webpack, GitHub, FullStory, Sentry, React Apollo, Terminal, Trello, Slack, Jira, Clubhouse

Languages

JavaScript, CSS, HTML, GraphQL, TypeScript, PHP, SQL, Sass

Frameworks

Redux, Jest, AngularJS, Next.js, React Native

Paradigms

Unit Testing, Agile Software Development, Functional Programming

Platforms

Drupal, Linux, Amazon Web Services (AWS), MacOS, Firebase, Visual Studio Code (VS Code), Vercel

Industry Expertise

Cybersecurity

Other

Styled-components, Front-end, User Interface (UI), Storybook, Styled System, Team Leadership, A/B Testing, Apollo, Apollo Server, Google Drive, Enzyme, Computer Science, SaaS, Machine Learning, UI Animation

Collaboration That Works

How to Work with Toptal

Toptal matches you directly with global industry experts from our network in hours—not weeks or months.

1

Share your needs

Discuss your requirements and refine your scope in a call with a Toptal domain expert.
2

Choose your talent

Get a short list of expertly matched talent within 24 hours to review, interview, and choose from.
3

Start your risk-free talent trial

Work with your chosen talent on a trial basis for up to two weeks. Pay only if you decide to hire them.

Top talent is in high demand.

Start hiring