Alexandr is available for hire

Alexandr Cosov

Verified Expert in Engineering

Front-end Developer

Sofia, Bulgaria

Toptal member since November 28, 2024

Expertise

React.js JavaScript TypeScript CSS Sass GraphQL Slack Development Zoom Development Tailwind CSS Twilio Development

Bio

Alexandr is a front-end developer with a strong foundation in JavaScript and TypeScript and extensive experience in React, Apollo GraphQL, HTML, CSS, and Sass. Committed to delivering real value to businesses, he specializes in testing with Jest and Cypress and state management with Redux and Zustand. Alexandr thrives on solving complex problems and is dedicated to continuously enhancing code quality, performance, and maintainability.

Portfolio

Toptal

JavaScript, TypeScript, HTML, CSS, React, Jest, Cypress, Sass, GraphQL, Nx...

Experience

React - 3 years
JavaScript - 3 years
TypeScript - 3 years
GraphQL - 3 years
HTML - 3 years
Sass - 3 years
CSS - 3 years
React Testing Library - 3 years

Availability

Part-time

Preferred Environment

Slack, Teams, Zoom, Google Meet

The most amazing...

...project I've participated in as a Toptal Core team member is HireGlobal. I was one of the project leaders and played a key role in developing the client portal.

Work Experience

Front-end Engineer

2021 - 2024

Toptal

Co-led the development of HireGlobal, a new service offering, and successfully built the client-facing portal, streamlining user access and enhancing the overall experience.
Played a key role in the creation of the Managed Delivery offering, contributing to the strategy and technical implementation.
Spearheaded the extraction of a chat system from an existing project, transforming it into a reusable component and enhancing efficiency and scalability across multiple applications.
Modernized state management by migrating from Redux to Zustand, which boosted performance and reduced complexity in the application architecture.
Enhanced continuous integration (CI) processes by optimizing GitHub Actions workflows, which reduced test run times on pull requests and accelerated overall development speed.

Technologies: JavaScript, TypeScript, HTML, CSS, React, Jest, Cypress, Sass, GraphQL, Nx, Tailwind CSS

Experience

Toptal's Client Portal

I served as a member of the team working on Toptal's Client Portal. The most notable visual parts of the portal I worked on are the permissions page, progress tracker, and TopChat widget and page.

Education

2018 - 2022

Bachelor's Degree in Information Technology, Mobile and Web Development

Collegium Da Vinci - Poznan, Poland

Skills

Libraries/APIs

React, React Testing Library

Tools

Slack, Zoom, Google Meet, Nx

Languages

JavaScript, TypeScript, HTML, CSS, Sass, GraphQL

Frameworks

Jest, Cypress, Tailwind CSS

Platforms

Twilio

Other

Teams, Computer Science

Collaboration That Works

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