Олександр

Oleksandr Maksymenko
Frontend Engineer React
Ukraine | [open contact info](look above in the "contact info" section) | [open contact info](look above in the "contact info" section)

Professional Summary
Frontend Engineer with 5+ years of experience building React, TypeScript, and Next.js applications. I specialize
in real-time interfaces, SSR, microfrontends, and design systems for fintech and high-scale web products. At
SpaceWhale, I made key frontend technical decisions for an R&D trading platform and delivered live pricing,
CRM, and shared tooling used by multiple teams. At Kyivstar, I helped migrate kyivstar.ua from a React SPA to
Next.js with SSR and supported the core project structure and abstractions. I also bring practical backend
experience with Node.js, NestJS, Prisma, and PostgreSQL when full-stack collaboration is needed.

Areas of Expertise
• Fintech and trading platforms
• Real-time data interfaces
• CRM and admin systems
• Microfrontends
• Design systems
• SSR and performance
• Node.js backend and REST APIs

Accomplishments
• Built a real-time pricing engine for 200+ symbol pairs with WebSocket updates up to 100 messages per
second.
• Scaled a CRM from 2 to 6 independently deployed microfrontends.
• Built a design system with 50 components used by 5 teams, cutting component work from about 4 hours to
about 1 hour.
• Created a CLI tool that cut new service setup from about 5 hours to 5 minutes.
• Grew automated test coverage to about 65% with 500+ Jest and Playwright tests.
• Helped move kyivstar.ua to Next.js with SSR for better indexing and performance.

Professional Experience
Frontend developer, SpaceWhale, Kyiv
Apr 2022 to Jul 2026
• Owned the frontend direction for an R&D trading platform built without formal specifications, translating
business goals into technical solutions and making key architecture decisions on the frontend side.
• Built the React/TypeScript trading interface for live price feeds, order flows, and financial calculations,
supporting 200+ symbol pairs with WebSocket updates up to 100 messages per second.
• Delivered CRM and admin workflows for internal teams, including user management, balance top-up and
withdrawal, credit logic, rewards, and analytics, while keeping the UI consistent across the platform.
• Scaled shared frontend tooling for 5 teams by building a design system, project generator, CI pipelines, and
test setup; the design system grew to 50 components and reduced component work from about 4 hours to
about 1 hour.
• Improved delivery quality by growing automated test coverage to about 65% with 500+ Jest and Playwright
tests.
Frontend developer, Kyivstar, Kyiv
Jun 2020 to Feb 2022
• Worked on kyivstar.ua, the website of Ukraine's largest telecom operator, contributing to a high-traffic public
frontend.
• Helped drive the migration from a React SPA to Next.js with SSR, improving indexing and performance
while shaping the project structure and core abstractions.
• Built and maintained the design system used across the website to keep the UI consistent and reusable.
• Mentored 2 developers through code reviews, onboarding, and knowledge-sharing sessions.

Technical Proficiencies

Frontend:React, Next.js, TypeScript, JavaScript, Redux Toolkit, Zustand, HTML5, CSS, SCSS, Styled
Components, MUI
Backend:Node.js, NestJS, REST API, WebSocket, Prisma, PostgreSQL
Architecture:Microfrontends, design systems, component libraries, CLI tooling
Testing:Jest, React Testing Library, Playwright
Tools:Git, Docker, CI/CD, Storybook, Claude Code

Languages
Ukrainian - Native, English - B2 (technical communication)

Licenses & Certifications
Certificate of completion: Claude code 101, Anthropic
Aug 2026 to Aug 2026
Certificate of completion: Claude 101, Anthropic
Aug 2026 to Aug 2026