Jobs at Prolific (Now Hiring) — 3,401 open — Page 83

HTML/CSS - Senior Developers - AI Training - Nottingham, UK

Remote OK

Senior$34M raised

HTML/CSS - Senior Developers - AI Training - UK About Prolific Prolific is not just another player in the AI space – we are building the biggest pool of quality human data in the world. Over 35,000 AI developers, researc…

Skills: HTML5, CSS3, Responsive Design, WCAG, BEM Methodology

Prolific

HTML/CSS - Senior Developers - AI Training - Newcastle upon Tyne, UK

Remote OK

Senior$34M raised

Skills: HTML5, CSS3, Responsive Design, WCAG, BEM Methodology

Prolific

HTML/CSS - Senior Developers - AI Training - Liverpool, UK

Remote OK

Senior$34M raised

Skills: HTML5, CSS3, Responsive Design, WCAG, BEM Methodology

Prolific

HTML/CSS - Senior Developers - AI Training - London, UK

Remote OK

Senior$34M raised

Skills: HTML5, CSS3, Responsive Design, CSS Grid, Flexbox

Prolific

Material Sciences - Graduates - AI Training

Remote Solely

$40/hr

Entry level$34M raised

Material Sciences - Graduates - AI Training - UK About Prolific Prolific is not just another player in the AI space – we are building the biggest pool of quality human data in the world. Over 35,000 AI developers, resear…

Skills: AI Evaluation, Materials Science, Fact-Checking, Technical Analysis, Scientific Visualization

Prolific

Italian - Fluent Speakers - AI Training - Trieste, Italy

Remote Solely

Entry level$34M raised

Italian - Fluent Speakers - AI Training - Italy About Prolific Prolific is not just another player in the AI space – we are building the biggest pool of quality human data in the world. Over 35,000 AI developers, researc…

Skills: Italian Fluency, AI Training, Content Analysis, Editing, Writing

Prolific

Italian - Fluent Speakers - AI Training - Reggio Calabria, Italy

Remote Solely

Entry level$34M raised

Skills: Italian Fluency, AI Training, Content Analysis, Editing, Writing

Prolific

Italian - Fluent Speakers - AI Training - Perugia, Italy

Remote Solely

Entry level$34M raised

Skills: Italian Fluency, AI Training, Content Editing, Content Writing, Analytical Thinking

Prolific

Italian - Fluent Speakers - AI Training - Modena, Italy

Remote Solely

Entry level$34M raised

Skills: Italian Fluency, AI Training, Content Editing, Content Writing, Analytical Thinking

Prolific

Italian - Fluent Speakers - AI Training - Parma, Italy

Remote Solely

Entry level$34M raised

Skills: Italian Fluency, AI Training, Content Analysis, Editing, Writing

Prolific

Italian - Fluent Speakers - AI Training - London, UK

Remote Solely

Entry level$34M raised

Italian - Fluent Speakers - AI Training - UK About Prolific Prolific is not just another player in the AI space – we are building the biggest pool of quality human data in the world. Over 35,000 AI developers, researcher…

Skills: Italian Fluency, AI Training, Content Analysis, Editing, Writing

Prolific

Italian - Fluent Speakers - AI Training - Edinburgh, UK

Remote Solely

Entry level$34M raised

Skills: Italian Fluency, AI Training, Content Analysis, Editing, Writing

Prolific

Italian - Fluent Speakers - AI Training - Bristol, UK

Remote Solely

Entry level$34M raised

Skills: Italian Fluency, AI Training, Content Analysis, Editing, Writing

Prolific

Italian - Fluent Speakers - AI Training - Brescia, Italy

Remote Solely

Entry level$34M raised

Skills: Italian Fluency, AI Training, Content Analysis, Editing, Writing

Prolific

Italian - Fluent Speakers - AI Training - Birmingham, UK

Remote Solely

Entry level$34M raised

Skills: Italian Fluency, AI Training, Content Editing, Content Writing, Analytical Thinking

Prolific

Italian - Fluent Speakers - AI Training - Argentina

Remote Solely

Entry level$34M raised

Italian - Fluent Speakers - AI Training - Argentina About Prolific Prolific is not just another player in the AI space – we are building the biggest pool of quality human data in the world. Over 35,000 AI developers, res…

Skills: Italian Fluency, AI Training, Content Analysis, Editing, Writing

Prolific

HTML/CSS - Senior Developers - AI Training - Leeds, UK

Remote OK

Senior$34M raised

Skills: HTML5, CSS3, Responsive Design, WCAG, BEM Methodology

Prolific

HTML/CSS - Senior Developers - AI Training - Glasgow, UK

Remote OK

Senior$34M raised

Skills: HTML5, CSS3, CSS4, Responsive Design, WCAG

Prolific

HTML/CSS - Senior Developers - AI Training - Edinburgh, UK

Remote OK

Senior$34M raised

Skills: HTML5, CSS3, Responsive Design, WCAG, BEM Methodology

Prolific

HTML/CSS - Senior Developers - AI Training - Coventry, UK

Remote OK

Senior$34M raised

Skills: HTML5, CSS3, Responsive Design, WCAG, BEM Methodology

HTML/CSS - Senior Developers - AI Training - UK

About Prolific

Prolific is not just another player in the AI space – we are building the biggest pool of quality human data in the world.

Over 35,000 AI developers, researchers, and organizations use Prolific to gather data from paid study participants with a wide variety of experiences, knowledge, and skills.

The role

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.

Researchers looking for your skills tend to pay up to $40/hr, depending on skills and experience. You must be prepared to complete paid tasks that require one hour of uninterrupted work, though many are shorter.

What you’ll bring

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.

What you’ll be doing in the role

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.

Why Prolific is a great platform to join as a Participant

Joining our platform as a Prolific participant will give you the chance to influence the AI models of the future using professional legal expertise. Once you pass our assessment, you can join Prolific in just 15 minutes, and start enjoying competitive pay rates, flexible hours, and the ability to work from home.

We've built a unique platform that connects researchers and companies with a global pool of participants, enabling the collection of high-quality, ethically sourced human behavioural data and feedback. This data is the cornerstone of developing more accurate, nuanced, and aligned AI systems.

We believe that the next leap in AI capabilities won't come solely from scaling existing models, but from integrating diverse human perspectives and behaviours into AI development. By providing this crucial human data infrastructure, Prolific is positioning itself at the forefront of the next wave of AI innovation – one that reflects the breadth and the best of humanity.

Links to more information on Prolific

Website

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Privacy Statement

By submitting your application, you agree that Prolific may collect your personal data for recruiting and global organisation planning. Prolific's Candidate Privacy Notice explains what personal information Prolific may process, where Prolific may process your personal information, its purposes for processing your personal information, and the rights you can exercise over Prolific use of your personal personal information.

About Prolific

LinkedIn Visit site

Building the biggest pool of quality human data in the world—for AI developers, researchers, and organizations.

Industry: Software Development
Company size: 51-200 employees
Founded: 2014
Headquarters: London
LinkedIn followers: 92,765
Total funding: $34M

Prolific is a technology company building the biggest pool of quality human data in the world—and the ultimate platform to access it. Over 35,000 AI developers, researchers, and organizations use Prolific to gather data from real, engaged participants—with a new study launched every 2 minutes. Prolific has been ranked among the fastest-growing businesses in the Financial Times 1000 in 2025 & 2024 and the Deloitte Technology Fast 50 in 2023.

Offices: London, GB · New York City, US · San Francisco, US

crowdsourcingparticipant recruitmentonline researchaidata collectiondata labelingai traininghuman dataglobal participant poolai model development

View all jobs at Prolific

Jobs at Prolific (Now Hiring) — 3,401 open — Page 83

HTML/CSS - Senior Developers - AI Training - Nottingham, UK

HTML/CSS - Senior Developers - AI Training - Newcastle upon Tyne, UK

HTML/CSS - Senior Developers - AI Training - Liverpool, UK

HTML/CSS - Senior Developers - AI Training - London, UK

Material Sciences - Graduates - AI Training

Italian - Fluent Speakers - AI Training - Trieste, Italy

Italian - Fluent Speakers - AI Training - Reggio Calabria, Italy

Italian - Fluent Speakers - AI Training - Perugia, Italy

Italian - Fluent Speakers - AI Training - Modena, Italy

Italian - Fluent Speakers - AI Training - Parma, Italy

Italian - Fluent Speakers - AI Training - London, UK

Italian - Fluent Speakers - AI Training - Edinburgh, UK

Italian - Fluent Speakers - AI Training - Bristol, UK

Italian - Fluent Speakers - AI Training - Brescia, Italy

Italian - Fluent Speakers - AI Training - Birmingham, UK

Italian - Fluent Speakers - AI Training - Argentina

HTML/CSS - Senior Developers - AI Training - Leeds, UK

HTML/CSS - Senior Developers - AI Training - Glasgow, UK

HTML/CSS - Senior Developers - AI Training - Edinburgh, UK

HTML/CSS - Senior Developers - AI Training - Coventry, UK

HTML/CSS - Senior Developers - AI Training - Nottingham, UK

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HTML/CSS - Senior Developers - AI Training - UK

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What you’ll be doing in the role

Key Technologies

Why Prolific is a great platform to join as a Participant

Links to more information on Prolific

Privacy Statement

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