Senior HTML/CSS Developer – AI Training (Remote)

About the role

Prolific is seeking senior HTML/CSS developers to join its Expert Network and help train cutting‑edge AI models. You will evaluate AI‑generated frontend code, provide feedback, and ensure high‑quality, accessible markup.

Key responsibilities

• Review AI‑generated HTML/CSS for functional correctness, semantic structure and best‑practice compliance.
• Validate the logical explanations supplied by the AI for layout and styling decisions.
• Render and test markup across browsers to confirm visual fidelity and accessibility.
• Annotate model performance, highlighting issues such as inaccessible markup, inefficient selectors or deprecated properties.
• Provide structured feedback to improve the model’s reasoning around responsive design and component architecture.

Required profile

• BSc or higher in Computer Science, Software Engineering, Web Development or a related field.
• Proven experience as a senior frontend developer or UI engineer specialising in HTML and CSS.
• Deep knowledge of the CSS cascade, specificity, box model, Flexbox, CSS Grid and WCAG accessibility standards.
• Commitment to delivering one‑hour uninterrupted paid tasks, with the ability to work remotely.

Required skills

• HTML5, CSS3/4 (custom properties, animations, modern layout systems).
• Expert use of BEM methodology, design tokens and responsive design techniques.
• Experience with Tailwind CSS, SASS/SCSS or CSS Modules.
• Proficiency with browser DevTools, accessibility auditing tools (axe, Lighthouse) and cross‑browser testing platforms.

What we offer

• Hourly compensation up to $40 per hour, based on skill and experience.
• Flexible, remote work on short, well‑defined tasks.
• Opportunity to influence the development of next‑generation AI models.