Freelancer profile translated to English.

Description

I transform your Figma mockups into high-performance code.

Specializing in custom Front-End development, I help demanding agencies and brands reconcile creative design with loading speed.

My "Brut Code" approach is simple: remove the superfluous to keep only the essential. Result: fluid, stable, and perfectly SEO-optimized sites.

💡 My added value for your projects:

Pixel-Perfect Integration: I respect your Artistic Direction to the millimeter. What you draw is what I code.

Obsessive Performance: I systematically aim for a 100/100 score (Core Web Vitals). No slowness, no endless loading.

Durable Code (Green IT): I use Vanilla HTML5/CSS3/JS without heavy frameworks. It's lighter for the server, and better for the planet.

🛠 Technical Stack: Semantic HTML5 | CSS3 (Grid/Flex/BEM) | Vanilla JavaScript | Git

🤝 Smooth Collaboration: Based in France, I integrate with your tools (Slack, Notion, Figma) with clear daily communication.

Let's discuss your next integration project.

Languages

Workplace preferences

Remote only

Primarily works remotely

Brut Code (Freelance)
Lead Developer - Brutalist Architecture (High Perf)
December 2025 - January 2026 (1 month)
Conception and complete development of the technical architecture for the "brut-code.com" site.

The Challenge: Create a strong visual experience without sacrificing performance.

Technical Results: • Google Lighthouse Score: 100/100 (Mobile & Desktop). • Loading Time: < 0.5 seconds. • Fluid UI Animations (60fps) hand-coded. • Native Dark/Light mode without libraries.
Web Performance Responsive Design HTML5/CSS3 UI/UX Design Figma
cassapresta
Expert Front-End Developer
January 2024 - Today (2 years and 5 months)
Marseille, France
Conception of high-performance web interfaces. Specialization in extreme optimization of Core Web Vitals (100/100 Score). Development in "Vanilla" HTML/CSS/JS to ensure lightness and fluidity. Eco-designed approach.

Be the first to recommend Leo

Help this freelancer shine by sharing your experience working together.

Agatha Frydrych

Backend Java Software Engineer

4.7

(3)

Baptiste Duhen

Fullstack developer

4.6

(4)

Amed Hamou

Senior Lead Developer

(2)

Audrey Champion

Web developer

4.3

(3)

Self-taught - Front-End Developer
Continuing Education & Technical Watch
2024
Apprentissage intensif et quotidien des standards du Web (W3C) et des langages natifs. Cursus personnel axé sur : Maîtrise approfondie du JavaScript Vanilla (sans Framework). Architecture CSS moderne (Flexbox, Grid, BEM). Optimisation des performances (Core Web Vitals). Accessibilité et SEO Technique. Formation basée sur la documentation officielle (MDN Web Docs) et la pratique par projets.

Leo Cassanelli

Expert Front-End Developer