> Markdown version of [/jobs/ext/2856408-developer-i-front-end](https://www.wearedevelopers.com/jobs/ext/2856408-developer-i-front-end). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md).

---

# Developer I (Front End)

- **Company:** Listing Type
- **Location:** Spain
- **Contract:** Permanent contract
- **Skills:** HTML, JavaScript (Programming Language), Cascading Style Sheets (CSS), Google Analytics, JQuery, SQL Databases, Google Tag Manager, Adobe Target, Git, Figma, Front End Software Development, Optimizely, Software Version Control
- **Published:** September 12, 2026
- **Apply:** https://eurojobs.com/jobs/27021849/apply

## About the Role

* HTML y CSS a nivel avanzado.
 * JavaScript con manipulación del DOM, incluyendo jQuery
 * Experiencia implementando tests con código propio en VWO (o herramientas equivalentes como Optimizely o Adobe Target).
 * Chrome DevTools para diagnóstico técnico.
 * Google Tag Manager.

Extras que nos gustaría

 * Google Analytics 4.
 * Figma.
 * Nociones de rendimiento web (Core Web Vitals, Lighthouse/GTmetrix).
 * SQL básico.
 * Herramientas de heatmaps o session recording (Hotjar, Clarity o similares).
 * Git / control de versiones.

Competencias transversales (soft skills)

 * Pensamiento analítico y orientación a datos
 * Comunicación técnica hacia perfiles no técnicos y hacia Desarrollo en su propio lenguaje.
 * Autonomía y proactividad: capacidad de detectar fricciones sin que se le asignen explícitamente.
 * Interés por el comportamiento del usuario.

## Description

* Implementar en VWO tests A/B y multivariante con código propio (HTML, CSS, JavaScript) a partir de hipótesis priorizadas por CRO.
 * Hacer QA de cada test: distintos navegadores/dispositivos, sin errores de consola ni efectos secundarios sobre la página.
 * Detectar y diagnosticar fricciones técnicas del funnel de conversión: errores de código, problemas de tracking mal implementado, tiempos de carga elevados.
 * Analizar resultados de los tests (VWO y GA4).
 * Apoyar en diseño de variantes (Figma) y en analítica (GA4).


## Related Videos

- [But, you're not Facebook](https://www.wearedevelopers.com/videos/378-but-you-re-not-facebook)
- [How a Small Team Shrank a Microsoft Monorepo by 94%](https://www.wearedevelopers.com/videos/1236-how-a-small-team-shrank-a-microsoft-monorepo-by-94)
- [The Resilience of the World Wide Web](https://www.wearedevelopers.com/videos/1281-the-resilience-of-the-world-wide-web)
- [Boost Productivity with AI: Figma & Playwright MCP Workflows - Aris Markogiannakis](https://www.wearedevelopers.com/videos/1768-boost-productivity-with-ai-figma-playwright-mcp-workflows-aris-markogiannakis)
- [Git for Code Reviews](https://www.wearedevelopers.com/videos/429-git-for-code-reviews)
- [NoLoJS - Avoiding JavaScript Cruft with HTML and CSS - Aaron T. Grogg](https://www.wearedevelopers.com/videos/1806-nolojs-avoiding-javascript-cruft-with-html-and-css-aaron-t-grogg)

## Related Articles

- [Dev Digest 133 - Back to Front](https://www.wearedevelopers.com/magazine/474-dev-digest-133-back-to-front)
- [Frontend Developer Salary in The UK](https://www.wearedevelopers.com/magazine/233-frontend-developer-salary-in-the-uk)
- [Dev Digest 120 - Apple and peers](https://www.wearedevelopers.com/magazine/455-dev-digest-120-apple-and-peers)
- [What is a web developer?](https://www.wearedevelopers.com/magazine/18-what-is-a-web-developer)
- [25 Essential Tools for Front End Developers](https://www.wearedevelopers.com/magazine/210-25-essential-tools-for-front-end-developers)
- [The Most Popular IT Jobs on the Market](https://www.wearedevelopers.com/magazine/376-the-most-popular-it-jobs-on-the-market)