Frontend Engineer

DesignBuildShip

Available for freelance work

FrontendPerformanceProduct DesignSystemsConversionArchitecture

Available40.4°N · Spain

WebsitesInterfacesSystemsLanding pagesProductsFrontendBuilt to last

I build fast, purposeful websites and digital products.

Design-trained. Product-minded. I work with agencies, startups and marketing teams that need more than someone who writes good code.

See my work Get in touch

What I do

What I bring to a project.

Available for freelance work

High-performance websites

Modern, fast websites built with Astro and React. SEO-ready, easy to maintain, designed to last longer than the project brief.

Landing & conversion systems

Pages for campaigns, launches and lead generation. Performance and conversion are not optional.

MarketingAffiliate

Product interfaces

Turning ideas and flows into clean, consistent interfaces. I think in components, states and systems — not isolated screens.

Design systems & UI foundations

Reusable component bases and token structures that let teams move faster without starting from scratch.

TokensComponents

Frontend architecture

Monorepos, shared packages, scalable structures. I care about how things are built — not just that they work today.

MonorepoTooling

How my work is organised

Three connected layers.

Where I write, share experiments and think out loud about building for the web.

FrontendDesignProductPerformanceSystemsOpen source

Juan Carlos

Studio layer — client workEnloLab

StrategyDesignFrontendPerformanceArchitectureBuilt to last

Technology layer

PerformanceProductCraft

For theBuildersShaping theWeb.

Building isn't just writing code — it's turning ideas, flows and constraints into products that perform. Design, execution and results, working together.

(Projects shipped)60+Websites, product interfaces and landing systems — built to perform and to last longer than the brief.

(Years building the web)8+

FrontendPerformanceProductSystemsConversion

(Graphic design)∞

BrandingVisual identityTypographyLayoutArt direction

Ready to build your next project?

Whether it's a website, a product interface or a campaign landing system — let's make something that works.

Start a project

Juan Carlos

Notes

On building for the web.

Why I no longer use Figma

designAIworkflowfrontend

saastro-relay: persistent memory for working with AI on real projects

AIMCPtoolingarchitecture

Design systems with AI: what changes and what doesn't

designAIsystems

UX writing: words are interface

UXwritinginterfaces