Frontend Engineer

¿Es usted el solicitante adecuado para esta ocasión? Descúbralo leyendo el resumen del puesto a continuación.

Frontend Engineer

Type: Freelance Hourly Contract

Location: Remote

This opportunity is for experienced Frontend Engineers and Full-Stack Developers interested in evaluating AI-generated web interfaces and code.

The work focuses on comparing AI-generated frontend implementations against real-world reference websites, assessing both visual fidelity and underlying code quality .

This is an evaluation-focused role rather than a traditional development position. Render a reference webpage and two AI-generated implementations at a 1920×1080 viewport and evaluate which version most accurately reproduces the reference.

Review the source code of AI-generated implementations and assess HTML structure, CSS architecture, responsiveness, maintainability, and implementation quality .

Test responsive behavior across different viewport sizes and identify layout or usability defects.

3–8 years of professional web development experience , primarily in frontend or full-stack engineering.

~ Strong hands-on experience with HTML, CSS, JavaScript, responsive web development, and modern frontend engineering practices .

~ Deep understanding of semantic HTML, Flexbox, CSS Grid, media queries, and responsive layouts .

~ Ability to read and understand both modern and legacy web layouts , including float-based and table-based designs.

~ Strong proficiency with browser Developer Tools , including DOM inspection, computed styles, viewport testing, and interactive state debugging.

~ Comfortable working from the command line, including extracting archives,



running local development servers, and troubleshooting asset paths .

~ Sufficient JavaScript knowledge to understand how scripts interact with the DOM and user interactions.

~ Strong professional written English and the ability to provide clear, detailed technical justifications .

~ Prior experience with RLHF, preference labeling, AI model evaluation, structured code review, or human-feedback projects .

Pixel-perfect design-to-code experience, including work with design systems, templates, or production web interfaces .

Knowledge of web accessibility , including ARIA, semantic landmarks, and heading hierarchy.

Familiarity with common failure patterns in AI-generated frontend code .

Experience with web scraping, website archiving, DOM parsing, or working with complex crawled website structures .

Previous experience completing AI evaluation projects and working in multi-hour evaluation sessions.

Ability to run a local development environment and static web server .

Important Project Requirements A functioning local development environment is required.

The role is intended for practicing web developers with strong frontend and UI implementation expertise.

Backend-only, ML/data-science-only, mobile-native-only, and DevOps-only backgrounds are generally not suitable for this evaluation work.

Independent contractor engagement.

Compensation is based on completed evaluation work in accordance with project requirements. Participate in Resume Evaluation & Interview Stage

Hay opciones de teletrabajo/trabajo desde casa disponibles para este puesto. xugodme

Hay opciones de teletrabajo/trabajo desde casa disponibles para este puesto.

📌 Frontend Software Engineer (Remote | Up to $90/hr) (Madrid)
🏢 Synthires
📍 Madrid