Demyd Hanenko

Senior JavaScript Engineer with 10+ years of experience building high-performance web and mobile applications in fintech, crypto, and SaaS. Expert in React, TypeScript, and scalable frontend architecture for high-load systems — with strong full-stack capabilities (Node.js, Laravel, WordPress). Known for taking full ownership of frontend delivery, driving cross-functional collaboration between design, backend, and product, and communicating technical decisions clearly to both engineers and stakeholders.

Proven track record of real-time data processing, performance optimization, and measurable impact on UX and delivery speed. Fully comfortable in async remote environments and international teams.

Senior React Developer + Node.js at Crypto Trading Terminal (2023-12 – 2026-03)

• Architected and led scalable frontend architecture for a real-time React + TypeScript trading platform serving 40k MAU.
• Built high-load web app, Chrome extension, and React Native mobile app from scratch as core React + TypeScript developer. Owned end-to-end frontend delivery across all platforms.
• Architected and led scalable frontend architecture for a real-time React + TypeScript trading platform (40k MAU) — defined component structure, state management patterns, and WebSocket data pipelines
• Built high-load web app, Chrome extension, and React Native mobile app from scratch as core React + TypeScript developer
• Owned end-to-end frontend delivery across all platforms — from architecture through QA and release
• Implemented real-time data processing pipelines for live price feeds, order execution, and TradingView chart integration
• Delivered performance optimization across the full frontend stack — reduced app response time by 73% and improved user conversion to first target action by 27%
• Mentored developers, conducted PR reviews, and defined frontend coding standards — maintaining 95.8% first-pass QA rate across average 21 tasks/sprint
• Collaborated with backend development (Node.js) by implementing API endpoints and data handling logic to support frontend features

Senior React Developer at BetSoftware (2022-02 – 2023-11)

Worked on high-load React platform serving 300k–500k MAU with focus on performance optimization and scalable component architecture.

• Worked on high-load React platform serving 300k–500k MAU — focused on performance optimization and scalable component architecture
• Implemented full UI redesign and UX improvements across core product flows
• Refactored legacy codebase and maintained unit test coverage with Jest

Senior React Developer at NDA (2021-04 – 2022-01)

Built DeFi applications and staking platforms with React + TypeScript and smart contract integration. Acted as frontend lead for a 3-person team.

• Built DeFi applications and staking platforms with React + TypeScript and smart contract integration
• Acted as frontend lead for a 3-person team — drove technical planning, architecture decisions, and delivery coordination across DeFi applications and crypto project websites
• Designed and developed websites for crypto projects (React, Next.js, Web3) — implemented real-time data processing for on-chain events

Middle Full-stack Developer at geoCapture (2020-06 – 2021-03)

Developed scalable logistics CRM portal and React Native mobile app with BLE device tracking and real-time backend synchronization.

• Developed scalable logistics CRM portal (Laravel, React, Next.js) with real-time data sync
• Built React Native mobile app with BLE device tracking and real-time backend synchronization

Middle Full-stack Developer at Lifeisgoodlabs (2017-05 – 2020-05)

Developed web applications using Laravel and WordPress; built mobile apps with Ionic. Participated in hiring, mentoring, and performance optimization.

• Developed web applications using Laravel and WordPress; built mobile apps with Ionic (Angular)
• Participated in hiring, mentoring, and performance optimization of legacy JavaScript projects
• Managed direct client communication across requirements, scoping, and delivery

Full-stack Freelancer at Upwork (2016-04 – 2017-04)

Delivered client projects using WordPress, Laravel, and Ionic; worked directly on requirements and delivery.

• Delivered client projects using WordPress, Laravel, and Ionic; worked directly on requirements and delivery

Junior Full-stack Developer at SITIO (2015-09 – 2016-03)

Developed WordPress sites.

• Developed WordPress sites

Master's in Artificial Intelligence – Kharkiv National University of Radioelectronics (2016-01 – 2018-01)

Bachelor's in Computer Science – Kharkiv National University of Radioelectronics (2012-01 – 2016-01)