Сергій

SERHIY LESHCHAK
Full-Stack Developer

SUMMARY SKILLS

I am a Full-Stack JavaScript Developer with 6 years of ● Front-End: JavaScript (ES5,
experience in software development. Purposeful, ES6), React,
Next.js, Redux, TypeScript,
professionally motivated, young, and looking for a
HTML, CSS,
professional company for long-term collaboration. Fast
SASS, LESS, React-Query,
learner with strong and flexible analytical thinking. React Context, Rest
API, OOP,
PROFESSIONAL EXPERIENCE Payment systems,
Tailwint CSS, Promises.
Group107
● Back-End: Node.js, Express,
Full-Stack Engineer | AUG 2024 – MAR 2026​ Mongo DB, Mongoose, SQL
Domain: Digital Accessibility Compliance Platform (basic), Redis, Payment
(WCAG / PDF/UA / Web Accessibility)​ systems, WebSocket, AWS,​
Architecture: React 18 + TypeScript SPA, Node.js Crypto billing(TRC-20)​
serverless backend, MongoDB, Amazon S3,​ ​
Amazon EC2, and real-time WebSocket workflows. ● AI technologies: Codex,
Cursor, Claude, Claude plugins,
Key Highlights: MCP
●​ Full-Stack development across frontend and
● Automation Testing: Jest,
backend layers Enzyme,
●​ Built scalable multi-tenant architecture with React Testing Library.
role-based access control
●​ Implemented core business logic for document ● Services: GitHub, GitLab,
lifecycle, users, and subscriptions Postman API, Git, Webpack,
●​ Developed real-time document processing with Axios.
live updates (WebSockets)
●​ Contributed to accessibility scanning and ● DevOps / CI/CD: GitHub
compliance reporting (WCAG & PDF/UA) Actions, GitLab CI (usage),
●​ Delivered enterprise features: company Automated Frontend Builds,
management, billing, APIs, notifications, and Tests, and Release Pipelines.
integrations
● Tools and Libraries: Tailwind
Product:​ CSS,
Material UI, Bootstrap, Ant
Accessibility4All Platform — Digital Accessibility
Design,
Compliance & Remediation Platform​
Lodash, VS Code, WebStorm,
Enterprise solution for PDF/UA and WCAG Mac OS.
compliance validation, website accessibility scanning,
 ● Developing from: Figma,
document remediation workflows, and regulatory
Photoshop,
reporting.
Zeplin, Illustrator.
Link: https://platform.accessibledocs.ai/log-in
● Agile: Scrum, Kanban, Agile,
Stack: TypeScript, React, Redux Toolkit, TanStack Lean.
React Query, Ant Design, SCSS Modules, Axios,
WebSocket, i18next, Recharts, Node.js, Express,
OpenAPI, MongoDB, AWS Lambda, Amazon S3,​
LANGUAGES
Amazon EC2, Playwright, Crawlee, Docker, Zoho
Billing, Sentry
English: Upper-intermediate​
Ukrainian: Native
Slovak: Upper-intermediate​
Axels
CONTACTS
Full-Stack JavaScript Developer | JUN 2022 – MAR
2024​ E-mail:
Domain: Educational Analytics Platform (EdTech / [открыть контакты](см. выше в блоке «контактная информация»)
Data-Driven Web App)​ Linkedin: Serhiy Leshchak
Architecture: React-based SPA, modular component Mobile number:
architecture, REST APIs, Node.js, MongoDB, Express [открыть контакты](см. выше в блоке «контактная информация»)
Key Highlights: Telegram: @SergoUFO73

●​ Developed and maintained scalable front-end EDUCATION
features using React Hooks and React Context.
●​ Built advanced filtering and reporting modules Uzhhorod National University
with interactive charts and analytics Bachelor's degree in
dashboards. Information Technology | SEPT
●​ Improved application accessibility in 2012 - JUN 2016
accordance with WCAG standards, enhancing
UX for users with disabilities.
●​ Implemented full UI test coverage using Jest,
Enzyme, and React Testing Library.
●​ Actively participated in code reviews and
architectural discussions to ensure long-term
maintainability.
●​ Mentored junior developers, improving
team-wide JavaScript and HTML/CSS
proficiency.
●​ Collaborated closely with back-end engineers
and Product Managers to refine usability and
product logic.

Related Project:​
Teaching Strategies — Educational Analytics
Platform​
A data-driven application connecting teachers,
children, and families to improve learning outcomes
through analytics and insights.​
Link: https://teachingstrategies.com/

Stack: JavaScript, TypeScript, Node.js, MongoDB,
Express, React, React Hooks, React Context,
Material-UI, Jest, Enzyme, React Testing Library, REST
API

StarApps
Front-End JavaScript Developer | AUG 2021 – MAY
2022​
Domain: Logistics & E-commerce Solutions
(High-Traffic B2B/B2C Platforms)​
Architecture: React + Redux SPA, TypeScript-enabled
codebase

Key Highlights:

●​ Developed front-end features for a logistics
management system using React, Redux, and
Material-UI.
●​ Designed and implemented complex editable
data tables for operational and logistics
workflows.
●​ Delivered a flexible calendar system for
planning and managing logistics events.
●​ Applied TypeScript in production environments
to improve reliability and maintainability.
●​ Contributed to a high-traffic e-commerce
project by delivering new features and resolving
UI and performance issues.

Related Project:​
Logistic Ways (HAVI) — Logistics & Supply Chain
Management Platform​
Application for procurement orders, delivery logistics,
packaging management, and supply chain event
planning.​
Link: https://www.havi.com/
Stack: JavaScript, TypeScript, Next.js, Redux,
Material-UI, Styled-Components

Boost Solutions
Front-End JavaScript Developer | MAI 2020 – AUG
2021​
Domain: Interactive Web Applications & Media
Platforms​
Architecture: React + Redux applications with
custom UI and Canvas-based rendering

Key Highlights:

●​ Developed production-ready front-end
applications using React and Redux.
●​ Built reusable UI components with
Styled-Components.
●​ Implemented custom interactive and visual
features using Canvas.
●​ Participated in code reviews and iterative
refactoring to improve performance and
maintainability.

Related Project:​
Drink Ripples — Beverage-Tech Media Platform​
Innovative platform enabling global Food & Beverage
brands to print images and messages on drink foam
for marketing and events.​
Link: https://www.drinkripples.com/

Stack: JavaScript, React, Redux, Electron,
Styled-Components, Canva.