Juan D.
Sevillano
Designer × Engineer × Explorer
7+ years building digital products, mobile apps, and Web3 solutions. Combining UX, engineering, and interactive design with a human-centered approach (HCI).
FULL-STACK
ARSENAL
A comprehensive toolkit for building modern, scalable digital experiences
Frontend / UI
- React / Next.js
- TypeScript
- React Three Fiber
- Tailwind CSS
- React Native
- Framer Motion
Backend & DB
- Node.js / Express
- NestJS
- PostgreSQL
- MongoDB
- Redis
- GraphQL / REST
Blockchain / Web3
- Solidity
- Ethers.js / Web3.js
- Hardhat
- Smart Contracts
- NFT Systems
- DeFi / Airdrop
Tools & Testing
- Git / GitHub
- Docker
- AWS / GCP
- Figma
- Jest
- Playwright
AI Agents & Tools
Design & HCI
Human-Computer Interaction as the foundation for creating intuitive, accessible, and emotionally engaging digital experiences.
THE
JOURNEY
THE VISION
I'm a hybrid designer and developer with 7+ years building digital products, mobile apps, complex systems, and Web3 solutions. I combine UX, engineering, and interactive design to solve real problems with a vision centered on humans (HCI).
Started as Full-Stack Developer
Built foundational expertise in modern web development, working on diverse projects from e-commerce platforms to real-time dashboards.
- →E-commerce with Stripe & Sabadell integration
- →Fast-food automation tools
- →COVID-19 dashboard for real-time data visualization
- →Electron desktop applications
Transitioned to Senior Roles
Stepped into senior positions, leading architecture decisions and mentoring teams. Focused on scalable systems and products serving thousands of users.
- →Architected CRM systems from scratch (Intercard Solutions)
- →Led frontend squads across multiple B2B verticals
- →Implemented comprehensive testing strategies
- →Designed reusable component systems
Entered Web3 & Blockchain Space
Expanded expertise into Web3, working with smart contracts, NFT ecosystems for DC Comics and Universal Music, and decentralized applications.
- →NFT collection management & minting pipelines for major brands
- →Smart contract auditing & optimization (Solidity)
- →High-performance booking systems using Web3
- →Microservices connected to Web3 infrastructure
Interactive Media Design Focus
Merged technical expertise with design thinking and HCI principles. Creating immersive digital experiences that prioritize usability, accessibility, and emotional engagement.
- →3D interactive experiences with React Three Fiber
- →Fluid animations & micro-interactions
- →Accessibility-first component systems
- →Design systems with narrative storytelling
Human-Computer Interaction
My approach is rooted in HCI principles: high-quality code as a solution for design, user-centered based solutions, and creating interfaces that feel natural and intuitive.
YOUR IDEA
MY EXPERTISE
From concept to launch, let's transform your vision into a powerful digital experience
Share Your Vision
What problem are you solving? Who are your users? Let's understand your goals.
Define Success
What does success look like? KPIs, timeline, and budget alignment.
Choose Your Path
Full-Stack, Web3, Interactive Design, or AI Integration? Let's pick the right stack.
Build Together
Agile development, constant communication, and iterative delivery.
What I Can Build For You
Full-Stack Apps
Web & mobile applications with modern tech stacks
Web3 Solutions
NFT platforms, smart contracts, DeFi applications
Interactive Design
3D experiences, animations, immersive UIs
Ready to Start?
Let's discuss your project. I typically respond within 24 hours.