Frontend UI Developer (React / Angular / Next.js / Svelte)

About OpenTrain

OpenTrain is the #1 platform for finding and building careers in AI training and data labeling. We connect skilled contributors with real projects that teach and refine AI systems, and we support people who want flexible, remote work in this fast-growing field.

About AI training and why it matters

AI training (data labeling, annotation, and human feedback) is the human side of building modern AI. Contributors create, review, and polish the examples that models learn from — from UI interactions to code-focused datasets — which makes this work a hands-on way to shape how AI behaves.

This role sits at the intersection of frontend engineering and AI training: you’ll build and refine interfaces that enable high-quality, reproducible labeling and evaluation work. The work is remote, often flexible, and a direct contribution to cutting-edge AI systems.

The role

We’re hiring a contract Frontend UI Developer with 2–4 years of professional frontend or full-stack experience to implement and polish user-facing features for web-based AI training tools.

You will focus on responsive, accessible, and performant components, collaborate with modern tooling and coding agents, and document your design and technical decisions so results are reproducible.

• Employment type: Contractor, part-time (remote, worldwide).
• Time commitment: Less than 20 hours/week (ideal 17–20 hrs/week); minimum availability ≥3 hrs/day.
• Pilot delivery expectation: able to meet a pilot pace of 2,500–5,000 items within 1 week.

What you'll do

Implement and refine user-facing features and components across web apps, focusing on usability and visual polish.

Optimize interfaces for accessibility, cross-browser compatibility, and performance; write clean, maintainable code and tests as appropriate.

Collaborate with coding agents and modern tooling (npm, bundlers, CI) and clearly document your reasoning and implementation choices so other contributors can reproduce results.

• Build responsive components and layouts using React, Angular, Next.js, or Svelte.
• Apply strong CSS skills (Tailwind or Bootstrap) to deliver refined UI/UX.
• Participate in code reviews and follow Git workflows.

Requirements

You must meet every listed requirement below; we will evaluate portfolio links and delivery speed/quality when making offers.

Education is preferred but not strictly required; please be honest about your background.

• 2–4 years professional frontend or full-stack development experience.
• Proficiency with at least one framework: React, Angular, Next.js, or Svelte.
• Strong CSS expertise (Tailwind or Bootstrap) and a keen eye for design and UX.
• Portfolio: provide 2–3 public web app URLs you built.
• English B1/B2 conversational proficiency with strong documentation skills.
• Familiarity with Git workflow and modern JS tooling (npm, bundlers, CI).
• Ability to deliver responsive, cross-browser, accessibility-minded interfaces.
• Availability: ideal 17–20 hrs/week; minimum ≥3 hrs/day.
• Capacity to meet pilot pace of 2,500–5,000 items within 1 week.
• Coding-agent experience (e.g., Lovable) is a plus but not required.

Who should apply

This role is a good fit if you enjoy front-end craftsmanship, care about UX details, and want part-time remote work that directly impacts AI training quality.

Apply if you can show public work, communicate clearly in English, and meet the delivery and availability expectations above.

• Entry-level to mid-level developers with a polished portfolio.
• Engineers who prioritize accessibility, performance, and reproducible documentation.
• Developers comfortable working with modern web stacks and fast pilot timelines.

Compensation, schedule, and next steps

Compensation is hourly and depends on portfolio strength, speed, and delivery quality. Baseline pay is $10–$30/hour; exceptional candidates may be offered $40–$50/hour based on portfolio, craftsmanship, and output.

This is a part-time contractor role, remote and worldwide. Ideal weekly availability is 17–20 hours, with a minimum of 3 hours per day. To apply, include 2–3 public web app links and a brief note describing which frameworks and CSS tools you used.

• Payment: PAY_PER_HOUR in USD.
• Provide portfolio links in your application.
• Be prepared to demonstrate speed and quality during an initial pilot.