Олександр

Kostushevych Oleksandr
Middle Frontend Developer | React.js | Next.js | TypeScript
LinkedIn: [відкрити контакти](див. вище в блоці «контактна інформація») | Phone: [відкрити контакти](див. вище в блоці «контактна інформація») | Email: [відкрити контакти](див. вище в блоці «контактна інформація») | Location:
Khmelnitsky, Ukraine | GitHub: github.com/AlexFoxi

I have 5 years of professional experience in frontend development, including 2 year working with React and Next.js. My
career started as a UI/markup developer building pixel-perfect interfaces for custom client websites. Over time, I gained
experience working with production-ready web applications using React.js, Next.js, TypeScript, JavaScript, Redux Toolkit,
REST APIs, SCSS, Styled-Components, Tailwind CSS, and performance optimization.

CORE SKILLS
Languages & Frameworks: Next.js, React.js, TypeScript, JavaScript (ES6+)
State & Forms: Redux Toolkit, RTK Query, React Hook Form
Styling/UI: SCSS, Tailwind CSS, Styled-Components, MUI, Responsive Web Design Cross-Browser Compatibility
API & Integrations: Axios, REST API, AWS S3 Signed URLs
i18n & Theming: i18next, next-intl, next-themes
Testing: Jest, React Testing Library, Cypress
AI Tools: Claude (Anthropic), ChatGPT (OpenAI), Google AI Studio — used daily for code review, refactoring, and
optimization
Tools: Git, ESLint, Prettier, Figma, Jira, Trello

EXPERIENCE

Frontend Developer · Space Scutum · (Dec 2025 – June 2026)
Cybersecurity SaaS · International product company
– Reducing the loading time of the toolbar page by about 2 times by introducing Next.js dynamic imports, lazy
loading modal components, and refactoring a monolithic page into a modular feature-based architecture.
– Improved media delivery performance by 80% by architecting a secure AWS S3 Signed URL pipeline: server-side
URL generation paired with client-side WebP image optimization — replacing a previously unoptimized public asset
flow.
– Resolved an authentication state bugs on the login page that caused incorrect validation behavior on route
transitions, eliminating unnecessary re-renders.
– Actively used AI tools (Claude, ChatGPT, Google AI Studio) throughout the development workflow — for code
review assistance, refactoring suggestions, and optimization — improving output quality and reducing time spent on
repetitive tasks.
– Collaborating with backend and mobile developers on REST API integration and improve data flow.
Stack: Next.js, TypeScript, React, Redux, Axios, React Hook Form, i18next, Prettier, Git, Jira.

Frontend Developer · IT Hoot · (Feb 2021 - Jul 2025)
▸ Frontend Developer Leroy Merlin Ukraine (Jun 2024 – Jul 2025)
Large-scale e-commerce · Adeo Group (top-3 DIY retailer in Europe)
– Developed and maintained production features using Next.js and TypeScript, including SSR-based pages and
dynamic UI components.
– Built reusable and scalable components to improve maintainability and reduce code duplication.
– Introduced ESLint and Prettier across the frontend team, standardizing code style and measurably reducing
PR review cycles and time-to-merge.
– Improved UX, enhanced app reliability, and ensured smoother communication between frontend and backend by
collaborating closely with backend developers and improving API integration using Next.js 14, and TypeScript.
– Implemented Google Analytics tracking according to technical specifications to support data-driven decision-
making.
Stack: Next.js, TypeScript, React, Redux, Axios, React Hook Form, Styled-Components, i18next, ESLint,
Prettier, TypeScript ESLint, Git, Figma, Jira

▸ Frontend / UI Development (Feb 2021 – Jun 2024)
– Developed responsive, pixel-perfect HTML/SCSS layouts for multiple client projects based on Figma and Zeplin
designs.
– Built reusable UI components and interactive elements (sliders, modals, custom inputs) using vanilla JavaScript.
– Ensured cross-browser compatibility and mobile-first responsiveness across all delivered interfaces.

EDUCAT ION

Master of Business Administration · Khmelnitsky National University · 2020
Bachelor of Management · Khmelnitsky National University · 2019

L ANGU AG ES

English: B2 – Upper-Intermediate | Ukrainian: Native