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Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md). --- # Javascript - Senior Developers - AI Training - San Francisco, USA - **Company:** Prolific, Inc - **Location:** San Francisco, CA, United States (Remote available) - **Experience:** Expert - **Salary:** $104,000.0 - **Contract:** Permanent contract - **Skills:** Clean Code Principles, JavaScript (Programming Language), Application Programming Interfaces (APIs), Artificial Intelligence, HTML5, Browser Compatibility, Cascading Style Sheets (CSS), Software Quality, Cyber Security, Computer Programming, Web Development, Machine Learning, Node.Js, Memory Leaks, Responsive Web Design, Semantic HTML, Software Engineering, TypeScript, Web Content Accessibility Guidelines, Tailwind, ReactJS, Model Validation, Cypress (Programming Language), Cross-Site Scripting (XSS), Backend, Vue.js, Syntactically Awesome Style Sheets (SASS), Webpack, AngularJS, Information Technology, Enterprise Integration, Figma, Graphql, Browser Testing, Front End Software Development, Restful APIs, Es2015 - **Published:** October 27, 2026 - **Apply:** https://www.careerbuilder.com/job-details/javascript-senior-developers-ai-training-san-francisco-usa-san-francisco-ca--1f49dc61-a88b-406a-b78a-052b1b46eca5 ## About the Role JavaScript, Artificial Intelligence (AI), Artificial Intelligence (AI), JavaScript, Data Collection, Training/Teaching, Testing, Software Engineering, Computer Science, Computer Security, * Education: a BS, MS, or PhD in Computer Science, Software Engineering, or a closely related technical field. * Professional Experience: professional experience building scalable web applications using JavaScript/TypeScript. * Coding Proficiency: ability to solve LeetCode Medium to Hard-level problems in JavaScript independently. * Deep Domain Knowledge: expert understanding of the Event Loop, closures, prototypical inheritance, and asynchronous patterns (Promises, async/await). * Code Quality: a high standard for clean code, including modularity, readability, and adherence to modern ES6+ standards. * Attention to Detail: ability to spot subtle logical flaws, memory leaks, or security vulnerabilities (e.g., XSS, prototype pollution) in model-generated code., * Core Language: expert mastery of JavaScript (ES6+) and TypeScript. * Frameworks: extensive experience with React, Node.js, Vue, or Angular. * Testing & Tools: proficiency with Jest, Cypress, Webpack, and Vite. * Backend & API: strong understanding of RESTful APIs, GraphQL, and server-side logic in a Node environment., * 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. * Attention to Detail: ability to spot subtle rendering issues, accessibility violations, specificity conflicts, or deprecated/non-standard usage in model-generated code, * 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. * Integration & API: strong understanding of how HTML/CSS interacts with JavaScript frameworks, CMS platforms, and design handoff tools such as Figma. ## Description We're looking for JavaScript Experts to join our Expert Network to help train and evaluate cutting-edge AI models using real engineering expertise. If you have the necessary experience, we'll send you a quick 10- to 15-minute test to assess your skills and suitability for AI tasks. If successful, you'll be invited to join Prolific as a participant, where you'll get paid to train and evaluate powerful AI models., * Evaluate Code Accuracy: review AI-generated JavaScript and TypeScript code for functional correctness and adherence to best practices. * Validate Logic & Reasoning: audit the step-by-step explanations provided by AI for complex algorithmic solutions to ensure they are logically sound. * Conduct Execution Testing: execute model-generated scripts in appropriate environments (Node.js or Browser consoles) to verify performance and output. * Annotate Model Performance: identify areas where a model provides inefficient solutions, deprecated syntax, or hallucinated library methods. * Refine Technical Logic: provide structured feedback on how models reason through frontend or backend architecture discussions., 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., * Core Languages: expert mastery of HTML5 and CSS3/4, including custom properties, animations, and modern layout systems.