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# HTML/CSS - Senior Developers - AI Training

- **Company:** Prolific, Inc
- **Location:** Seattle, WA, United States (Remote available)
- **Experience:** Expert
- **Salary:** $83,200.0
- **Contract:** Permanent contract
- **Skills:** Artificial Intelligence, HTML5, Browser Compatibility, Cascading Style Sheets (CSS), Software Quality, Computer Programming, Web Development, Responsive Web Design, Semantic HTML, Software Engineering, Web Content Accessibility Guidelines, Tailwind, Model Validation, Syntactically Awesome Style Sheets (SASS), Information Technology, Browser Testing, Front End Software Development
- **Published:** August 1, 2026
- **Apply:** https://www.careerbuilder.com/job-details/html-css-senior-developers-ai-training-seattle-usa-seattle-wa--b00d3b70-cfe8-4855-8ccf-41048ce60dcb

## About the Role

* Educational Background: a BSc or higher in Computer Science, Software Engineering, Web Development, or a closely related technical field.
 * Professional Experience: real-world experience as a Senior Frontend Developer or UI Engineer specialising in HTML/CSS.
 * Coding Proficiency: ability to independently build complex, responsive layouts and components without relying on frameworks or libraries.
 * Deep Domain Knowledge: expert understanding of the CSS cascade, specificity, the box model, Flexbox, CSS Grid, accessibility standards (WCAG), and cross-browser compatibility.
 * Code Quality: a high standard for clean, semantic markup and maintainable CSS, including adherence to BEM methodology, design tokens, and modern CSS standards.

## Description

We're looking for Senior HTML/CSS Developers to join our Expert Network to help train and evaluate cutting-edge AI models. If you have a background in Software Engineering or Frontend Development, we'll send you a quick 10- to 15-minute test to assess your skills. If successful, you'll be invited to join Prolific as a participant, where you'll get paid to help AI understand and produce high-quality frontend code and design implementation., * Evaluate Code Accuracy: review AI-generated HTML/CSS for functional correctness, semantic structure, and adherence to best practices.

 * Validate Logic & Reasoning: audit the step-by-step explanations provided by AI for layout solutions and styling approaches to ensure they are technically sound.
 * Conduct Execution Testing: render model-generated markup and stylesheets in appropriate environments to verify visual output and cross-browser behaviour.
 * Annotate Model Performance: identify areas where a model produces inaccessible markup, inefficient selectors, deprecated attributes, or hallucinated CSS properties.
 * Refine Technical Logic: provide structured feedback on how models reason through responsive design, component architecture, or design system implementation.

Key Technologies

 * Core Languages: expert mastery of HTML5 and CSS3/4, including custom properties, animations, and modern layout systems.
 * Frameworks & Methodologies: extensive experience with Tailwind CSS, SASS/SCSS, or CSS Modules, and familiarity with component-driven design systems.
 * Testing & Tools: proficiency with browser DevTools, accessibility auditing tools (e.g., axe, Lighthouse), and cross-browser testing platforms.


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