
Eduard Varabei
Verified Expert in Engineering
Full-stack Engineer and Developer
Sarasota, United States
Toptal member since July 8, 2026
Eduard is a senior full-stack engineer and tech lead with 10+ years of experience building scalable fintech, crypto, payments, and healthcare platforms. He's an expert in React, React Native, Next.js, TypeScript, fullstack architecture, and performance optimization. He's also experienced with Web3, Node.js, GraphQL, AWS, AI-powered products, and distributed systems, having mentored teams of 15+ engineers across 5 teams to deliver high-impact products from MVP to enterprise scale.
Portfolio
Experience
- JavaScript - 12 years
- Performance Optimization - 10 years
- TypeScript - 10 years
- REST APIs - 10 years
- React - 8 years
- Next.js - 6 years
- Tailwind CSS - 5 years
- GraphQL - 4 years
Preferred Environment
Docker, Google Cloud Platform (GCP), CircleCI, Jenkins, Amazon Web Services (AWS), Webpack, Artificial Intelligence (AI)
The most amazing...
...platform I've launched is a Kraken ramp crypto-to-fiat platform, which generated over $3 million in monthly transaction volume after its release.
Work Experience
Senior Software Engineer
Kraken
- Led the 0 to 1 development and launch of a fiat-to-crypto platform built on Kraken's infrastructure, owning front-end architecture and delivery.
- Defined front-end architecture, CI/CD strategy, and engineering standards to improve scalability, reliability, and developer productivity.
- Delivered payment infrastructure integrations including Apple Pay, Google Pay, LATAM payment methods, and Plaid RTP across web and mobile platforms.
- Implemented feature flagging, experimentation, analytics, and a centralized payment orchestration layer for transaction processing and error handling.
- Established security, release, and operational processes, supporting production readiness, platform stability, and ongoing feature delivery.
Staff Front-end Engineer, React Architect
Acrisure
- Led the migration from React 16 to React 18 for a healthcare platform serving 500,000+ monthly active users.
- Reduced front-end bundle size by 37% through code splitting, tree shaking, and Webpack 5 optimization.
- Improved Largest Contentful Paint (LCP) by 35% using concurrent rendering and front-end performance optimization techniques.
- Built and maintained a reusable UI component library with 50+ shared components.
- Modernized front-end infrastructure by migrating from Webpack 4 to Webpack 5.
- Optimized CI/CD pipelines, reducing deployment time by 60%.
Front-end Team Lead
Magic Powered
- Led front-end development across fintech, real estate, and Web3 products.
- Built reusable UI systems and implemented Auth0-based multi-tenant authentication for B2B applications.
- Contributed to PCI DSS Level 1 compliance initiatives and payment platform integrations.
- Improved engineering productivity through TypeScript adoption, Jest testing, and front-end architecture standardization.
- Delivered AI-powered real estate analysis tools processing 1,000+ property parameters (Mobile First and PWA apps).
- Built and optimized scalable React/React Native applications, including NFT marketplace infrastructure and wallet integrations.
- Mentored engineers, conducted code reviews, and participated in system design decisions.
Team Lead (Payments)
BillingPlatform
- Led development of a customer payments portal for enterprise billing systems.
- Implemented white-label branding capabilities and 50+ reusable React widgets.
- Modernized legacy front-end architecture, reducing application load time by 70%.
- Contributed to award-winning platform initiatives recognized by CODiE Awards 2022.
Senior Front-end Engineer
BillingPlatform
- Migrated legacy front-end systems to React and TypeScript.
- Developed Node.js services and payment platform integrations.
- Integrated six payment providers supporting $10+ million in annual transaction volume.
- Improved front-end app performance by 20% through rendering and architecture optimizations.
- Reduced production issues by 30% through TypeScript adoption and improved code quality practices.
Front-end Engineer
50x.com
- Developed front-end applications for high-volume crypto trading platforms handling 5,000+ daily transactions.
- Moved JS to the TS codebase and adopted React Native for mobile users. Improved application loading performance by 30%.
- Built internal tools, exchange integrations, and file upload systems supporting 1,000+ monthly users.
- Contributed to MVP delivery, feature implementation, and platform scalability improvements.
Technical Lead
Wanter LLC
- Led development of early-stage B2B startup platforms from concept to MVP launch.
- Designed system architecture, front-end/back-end infrastructure, and database solutions.
- Built full-stack web applications and core platform features.
- Conducted A/B testing and contributed to product strategy and user experience improvements.
- Mentored engineering team members and participated in technical hiring decisions.
- Supported investor presentations and early-stage product demonstrations.
- Supported acquisition of the first 30 B2B clients and improved local business service discovery workflows.
Software Engineer
Hypersoft
- Built 40+ reusable components for analytics. Implemented map layers algorithms with custom geohash.
- Wrote big SQL queries optimization (20% faster analytics for 1+ million data points).
- Added CI/CD level and service levels. Did refactoring and created a UI codebase for custom clients' needs.
Experience
MyDMVExam.com
https://mydmvexam.com/As chief technology officer (CTO), I led the platform's technical vision, architecture, and execution from concept to production. I designed and oversaw the development of the application's back-end and front-end systems, established scalable cloud infrastructure, implemented secure authentication and data management, and optimized performance for high availability and responsiveness. I directed engineering efforts, defined development standards, managed technical roadmaps, and collaborated closely with product and business stakeholders to deliver new features and continuously improve the platform. My leadership ensured the system remained secure, maintainable, and capable of supporting the platform's growth and long-term success.
Website-Whitelist.com
https://website-whitelist.comAs the chief technology officer (CTO), I was responsible for defining the platform's technical strategy and leading its end-to-end development. I architected the application, designed the back-end services and browser extension framework, implemented secure data storage and synchronization mechanisms, and established scalable cloud infrastructure to support growing user adoption. I oversaw the engineering team, introduced development best practices, ensured compliance with modern security standards, optimized performance across supported browsers, and drove the continuous delivery of new features and product improvements.
Medittate
http://medittate.com/As the chief technology officer (CTO), I defined the platform's technical strategy and led its end-to-end development. I architected the mobile application, back-end systems, and cloud infrastructure supporting personalized content delivery, subscription management, analytics, and secure data storage. I established engineering best practices, implemented CI/CD pipelines, optimized performance, and ensured the platform met high standards for security, reliability, and scalability. I also led the engineering team and collaborated closely with product and business stakeholders to deliver new features and drive the platform's continued growth.
Education
Bachelor's Degree in Computer Engineering
Belarusian State University of Informatics and Radioelectronics - Belarus
Bachelor's Degree in Computer Programming and Software Development
Baranovichi State College of Light Industry - Belarus
Skills
Libraries/APIs
React, Node.js, REST APIs, Zod, Playwright, Web3.js, WebExtensions API
Tools
Webpack, Auth0, Expo, CircleCI, Jenkins, GitLab, Claude Code, Webpack 5, Plaid
Languages
TypeScript, JavaScript, GraphQL, SQL, PHP, XML, C#
Frameworks
Jest, React Native, Next.js, Tailwind CSS, Cypress, Redux, NestJS, ASP.NET
Paradigms
E2E Testing, Unit Testing
Platforms
Maestro, Amazon Web Services (AWS), Blockchain, Docker, Mobile, Google Cloud Platform (GCP)
Storage
NoSQL, Redis
Other
CI/CD Pipelines, TanStack, Performance Optimization, i18n, Payments, Sagas, Design, Artificial Intelligence (AI), Apple Pay, Google Pay, Ethers.js, Solana, Extensions, Software Development
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