React and Next.js AI Code Review Engineer

About OpenTrain

OpenTrain is the #1 platform for people who build careers in AI training and data labeling. We help specialists find and grow long-term freelance work evaluating and improving AI systems, consolidate projects in one profile, and turn technical expertise into repeatable contract work.

Why AI training matters (brief)

AI training is the human side of building modern models: people create, review, and rate examples that teach AI systems to write code, interpret interfaces, and follow best practices. This work is remote, flexible, and lets you directly influence how state-of-the-art tools behave.

• Remote and flexible: work from anywhere with a computer and internet.
• Impactful: your technical judgments shape model behavior and developer-facing outputs.
• Accessible: many roles expect domain knowledge and careful, repeatable evaluation work.

The role

We are recruiting a React and Next.js AI Code Review Engineer to evaluate AI-generated frontend code and explanations, produce high-quality reference implementations, and rate model outputs for correctness and best practice. This is contractor, hourly work focused on advanced frontend engineering topics.

• Review AI-generated React and Next.js code for correctness, readability, accessibility, security, and performance.
• Create clear, production-ready reference solutions and explanatory write-ups.
• Compare and rate multiple AI responses for technical accuracy and reasoning quality.

What you'll do day-to-day

Your work will center on careful technical review and high-quality content creation for AI training workflows. Expect a mix of hands-on code review, writing model solutions, and structured evaluation tasks where you score and compare model outputs using defined rubrics.

• Identify issues in rendering behavior, state management, routing, data fetching, hydration, caching, and bundle efficiency.
• Judge reasoning quality and technical accuracy across alternative AI responses.
• Write model solutions and explanatory text that serve as reference answers for training data.

Required skills and experience

Candidates must have professional frontend engineering experience with React and Next.js and be comfortable explaining technical trade-offs in English. Prior experience with AI data training is a plus but not required.

• Strong professional experience with React and Next.js, including modern React patterns and Next.js App Router concepts.
• Deep understanding of web fundamentals: HTTP, browser rendering, security basics, cookies, sessions, and OAuth flows.
• Practical experience with testing and quality tools: Jest, Vitest, React Testing Library, Playwright, Cypress, linting, and CI/CD.
• Experience with code review, performance optimization, accessibility, and clear technical writing in English.
• Prior AI data training, annotation, or evaluation experience is a strong plus.

Helpful background (nice-to-have)

You’ll stand out if you’ve built production React apps at scale or have deep familiarity with Next.js runtime behaviors and deployment patterns. Accessibility and performance expertise are especially valuable when judging model outputs.

• Experience with SSR, SSG, ISR, Server Components, middleware, caching, and deployment patterns.
• Familiarity with accessibility standards: keyboard navigation, ARIA, focus management, semantics, and contrast.
• Background building production web applications with React at scale.

Role details & how to apply

This is an hourly, contractor position paid at $90 USD per hour. The role is fully remote, requires English-language work, and expects roughly 20+ hours per week. Open to candidates in multiple countries (listed below).

• Employment type: Contractor, Part-time.
• Rate: $90 USD per hour (paid hourly).
• Time requirement: 20+ hours per week.
• Languages: English required.
• Eligible countries: BD, BT, BR, KH, DE, IN, ID, MY, NP, PK, SG, LK, TH, PH, US, TL, VN.