Frontend Web Developer — JavaScript/TypeScript & React

About OpenTrain

OpenTrain is the #1 platform for finding and building careers in AI training and data labeling. We help people start and grow careers teaching AI by connecting contributors with projects across the industry and providing tools to build a professional profile and apply quickly.

OpenTrain contributors work remotely on flexible schedules and play a direct role in how modern AI systems are built and evaluated.

About AI training and why it matters

AI training (data labeling/annotation) is the human work behind machine learning: people prepare, review, and refine examples that teach models to understand language, images, audio, and code. This work is fast-growing, accessible, and offers flexible remote opportunities.

Although this role is engineering-focused, you will be contributing to projects that require human reviewers and engineers to craft high-quality interfaces and components that support AI-powered products and workflows.

The role

We are hiring frontend developers and full-stack engineers to build, refine, and maintain elegant, high-performance web interfaces used across OpenTrain projects. We plan to hire up to 30 developers as contractors on part-time engagements.

You will translate designs into responsive, production-ready components, enforce accessibility and UI/UX best practices, improve existing implementations, document technical decisions, and collaborate with project operations to deliver to spec and on time.

What you'll do day to day

Deliver pixel-perfect UI from Figma/Sketch mockups and maintain consistent design-system components across applications. Ensure performance, accessibility, and cross-browser compatibility in production builds.

Review and improve existing implementations, write clear documentation explaining trade-offs and reasoning, and work with operations to meet deadlines and requirements.

• Convert Figma/Sketch mockups into responsive, production-ready components.
• Implement and maintain design-system components (Tailwind, Bootstrap, Material UI).
• Optimize frontend performance and ensure cross-browser compatibility.
• Enforce accessibility best practices and deliver smooth interactions.
• Document implementation choices and communicate clearly with stakeholders.

Requirements

You must meet every mandatory requirement below; applications missing the required portfolio link will not be reviewed.

This role requires strong written English (C1 or higher) because clear documentation and collaboration are essential.

• 2–6 years professional frontend or full-stack experience.
• Proficiency in JavaScript and TypeScript.
• Expertise with one or more frameworks: React, Next.js, Vue, or Angular.
• Advanced HTML5/CSS3 and responsive layout skills.
• Experience with design systems: Tailwind, Bootstrap, or Material UI.
• Demonstrable eye for visual detail and usability; able to deliver pixel-perfect UI.
• Ability to convert Figma/Sketch mockups into production-ready components.
• Solid understanding of performance optimization and cross-browser compatibility.
• Clear written communication and ability to document reasoning and trade-offs.
• Availability for a minimum of ~17–20 hours/week (preferred ~4 hours/day).
• A public, live portfolio link (Dribbble, Behance, GitHub Pages, CodePen, Vercel, etc.) is mandatory; private links, files, or screenshots are not accepted.

Compensation & commitment

Pay is $35 USD per hour. Roles are contractor, part-time engagements with a minimum expected commitment of about 17–20 hours per week (ideally ~4 hours per day).

Work is remote and open to applicants worldwide. Multiple hires will be made to staff ongoing projects.

How to apply

Apply with your resume/CV and include a public, live portfolio URL in your application. Applications that do not include a public link will not be reviewed.

Do not send files, screenshots, or private links—only public URLs. During interviews you will be asked to paste the same public portfolio URL for verification.

• Include your public portfolio URL (Dribbble, Behance, GitHub Pages, CodePen, Vercel, etc.).
• Be prepared to discuss specific projects, implementation details, and decisions during the interview.
• Expect questions about accessibility, performance optimization, and converting designs to code.