Robert Eduardo Medina Carvajal

Freelance / Team leader fron-end

About

Senior Frontend Developer | React Ecosystem Specialist | 6+ Years Experience I'm a frontend engineer with 6+ years building production-grade applications using React, React Native, and Next.js. I specialize in creating scalable, performant, and well-tested web and mobile solutions. 🔧 Core Stack: • Frontend: React 19, Next.js 15, React Native (Expo 54) • State Management: TanStack Query v5, Zustand • Languages: TypeScript (strict mode), JavaScript ES6+ • Testing: Jest, React Testing Library (94% coverage achieved) • Architecture: Clean Architecture, SOLID principles, multi-tenant systems 💼 Recent Achievements: • Built multi-tenant SaaS platform serving 1000+ users with React 19 + Next.js 15 • Developed cross-platform mobile apps (iOS/Android) with React Native achieving 94% test coverage • Implemented AI-powered features (predictive navigation, smart caching) improving UX by 78% • Architected scalable APIs integration with TanStack Query reducing API calls by 60% 🎯 Technical Strengths: • Performance optimization (Core Web Vitals, Lighthouse scores 90+) • Real-time applications (WebSocket, Server-Sent Events) • Payment integrations (Stripe, multi-currency support) • Internationalization (i18n, multi-language support) • CI/CD pipelines (GitHub Actions, automated testing) 📚 Additional Skills: • Backend: .NET 8, REST APIs, database design • Cloud: AWS basics, deployment automation • Web3: DeFi protocols, blockchain integration (learning) I'm passionate about code quality, developer experience, and shipping features that users love. Always open to collaborating on challenging projects that push technical boundaries. Let's build something amazing together! 🚀

Country

Spain

City

Madrid

Industry

Computer Software

Skill

React Native, Solidity, Principios SOLID, Three.js, reactjs, Firebase, Tailwind CSS, JavaScript, React.js, Amazon Web Services (AWS), GraphQL, Jest, web 3, Next.js, Desarrollo de software, Desarrollo front end, TypeScript, LAMP, SQL, GitHub

Experience

Freelance / Team leader fron-end

Playtopia

2025-1 - Present · 1 yr 9 mos

Madrid

I help startups and businesses build production-ready web and mobile applications with measurable results. Specialized in modern JavaScript ecosystems with a focus on code quality, testing, and scalability. 💼 Current Engagement: Tech Lead at Playtopia - Multi-Tenant SaaS Platform • Architecting React 19 + Next.js 15 admin dashboard serving 1000+ active users • Built React Native mobile apps (iOS/Android) with 877 automated tests (94% coverage) • Reduced API calls by 60% through TanStack Query optimization • Implemented AI-powered features improving user retention by 78% • Achieved Lighthouse performance scores of 90+ across all applications 📊 Quantifiable Results I Deliver: ✅ 94% average test coverage (Jest + React Testing Library) ✅ Page load times < 2 seconds (Core Web Vitals optimization) ✅ 60% reduction in API overhead through smart caching strategies ✅ Zero critical bugs in production (comprehensive testing + TypeScript strict mode) ✅ 3x faster development cycles with reusable component libraries 🛠️ Technical Stack: • Frontend: React 19, Next.js 15, React Native (Expo), Vue.js, Astro • State Management: TanStack Query v5, Zustand, Pinia • Languages: TypeScript (strict), JavaScript ES6+ • Backend: Node.js, .NET Core (API integration) • Testing: Jest, Vitest, Playwright (E2E) • Architecture: Clean Architecture, SOLID principles, micro-frontends

Frontend developer

BM BOT Solutions

2022-9 - 2023-3 · 7 mos

Caracas, Distrito Federal, Venezuela

As a Frontend Web Application Developer, I led innovative projects in ReactJS, SASS, and agile methodologies. Specializing in Web 3.0, I implemented smart contracts, non-fungible tokens, and blockchain. I achieved a 20% increase in NFT collection sales, demonstrating my positive impact on business goals.

Freelance

Visibilitytech

2021-1 - 2022-6 · 1 yr 6 mos

Puerto Varas, Los Lagos, Chile

During my time at Visibilitytech, I led web development projects using JavaScript, ReactJS, AngularJS, JSON, NodeJS, and TypeScript. My focus was on advanced technological solutions, project management, software architecture, and code quality. I acquired skills in REST, Web Services, Vue, Node.js, media management, and text processors. I optimized processes and improved media management to increase client acquisition by understanding the business flow.

Coordinator of Control and Logistics

techsolutiongroups

2019-4 - 2022-4 · 3 yrs 1 mo

Chile, Los Lagos, Puerto Montt

During my time as the national manager of all the company's technicians in Chile, Panama, and Honduras, I was responsible for various tasks, including programming, project development and reporting, as well as the installation of networks and telecommunications in both private and public companies. I succeeded in acquiring new clients and enhancing the reliability of our network and telecommunications solutions.

IT Systems Analyst III

Industria Canaima

2017-1 - 2018-1 · 1 yr 1 mo

Caracas, Distrito Federal, Venezuela

As the person in charge of server maintenance, IT support, and internal systems development in various languages, I led the successful implementation of a production control system using JavaScript, Html 5, and Css 3, supported by the PostqreSQL database. This project resulted in a significant increase in efficiency and control in tablet deliveries, maximizing assembly times.