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 shape how modern AI systems behave and provide a place to grow your profile, showcase work, and apply quickly. Creating an OpenTrain account is free.

Why AI training and this role matter

AI training is the human side of building intelligent software: people annotate data, refine model outputs, and craft UX that makes systems useful. Contributors work remotely on flexible schedules and directly influence how state-of-the-art products behave.

This role focuses on frontend engineering for web applications that support AI-training workflows and tools. Your UI craftsmanship will improve usability, accessibility, and developer handoff—work that impacts both contributors and the models they train.

The role

We’re hiring a contract Frontend UI Developer to implement and refine user-facing features, build responsive components, and polish interfaces for usability and visual quality. This position is part-time and remote (worldwide). You’ll write maintainable code, optimize for accessibility and performance, and document your reasoning so others can reproduce results.

What you’ll do

You’ll work directly on the frontend: shipping components, improving layouts, and ensuring consistent UX across browsers and devices. Collaboration with teammates and coding agents is part of the workflow, and you will use modern JavaScript tooling and Git-based collaboration.

• Implement and refine responsive UI features and components.
• Polish visual design and micro-interactions to improve usability.
• Optimize for accessibility (a11y) and cross-browser compatibility.
• Profile and improve frontend performance where needed.
• Write clear documentation and reproducible explanations of your decisions.
• Collaborate with automated coding agents and team tooling when applicable.

Requirements

Candidates must meet the stated experience and technical requirements below. We will evaluate portfolio strength and delivery quality when considering higher pay tiers.

• 2–4 years professional frontend or full‑stack development experience.
• Proficiency with at least one framework: React, Angular, Next.js, or Svelte.
• Strong CSS skills and tooling experience (Tailwind or Bootstrap preferred).
• A keen eye for design and UX; attention to visual polish and usability.
• Clear English communication at B1/B2 (conversational) and strong written documentation.
• Comfortable with Git workflows and modern JavaScript tooling (npm, bundlers, CI).
• Delivers responsive, cross-browser, and accessibility-minded interfaces.
• Portfolio: include 2–3 public web app URLs you built.
• Availability: ideally 17–20 hrs/week (target ~8 hrs/day); minimum ≥3 hrs/day.
• Able to meet pilot pace of 2,500–5,000 items within 1 week when required.
• Coding-agent experience (e.g., Lovable) is a plus but not required.

Compensation & schedule

This is a part-time contractor role. Baseline pay ranges from $10–$30 per hour. Exceptional developers with strong portfolios, fast delivery, and outstanding UX craftsmanship may be considered for higher pay—up to $40–$50 per hour based on portfolio strength and delivery quality. Exact rates will be set per engagement.

The role is remote and flexible, but you should be able to commit to the stated weekly hours and the pilot delivery pace when requested.

Who should apply

Apply if you’re an early-career frontend developer or full-stack engineer with solid hands-on experience building web apps, a portfolio of public projects, strong CSS and UX sensibility, and the ability to document and explain your work. This is a good fit for people who want flexible, remote contract work that directly affects AI training tools and outcomes.

How to apply

When you apply, include links to 2–3 public web apps you built and a short note about the most relevant framework you used (React/Angular/Next.js/Svelte), your CSS tooling (Tailwind or Bootstrap), and any experience with coding agents or automated tooling.

We will review portfolios and may ask for a short task or code walkthrough to evaluate fit and set final compensation.