About the job
Mercor connects elite creative and technical talent with leading AI research labs. Headquartered in San Francisco, our investors include Benchmark , General Catalyst , Peter Thiel , Adam D'Angelo , Larry Summers , and Jack Dorsey .
Position: Frontend Engineer
Type: Contract
Compensation: $90/hour
Location: Remote
Role Responsibilities
Render a reference page and two candidate replications at 1920×1080. Judge which is the closer reproduction, state by state.
Diff visual fidelity in detail: box model and spacing, typography (family, size, weight, line-height, letter-spacing), color and border treatment, image and asset handling, z-order, and overflow.
Read the source of both attempts and grade construction quality. Distinguish a replication that is genuinely correct from one that merely looks correct at one viewport.
Test responsiveness. Identify defects such as a nav bar that looks right at 1920px but collapses at 1400px.
Write specific, evidence-cited justifications for every preference. Provide detailed explanations like "B nests the article body in a single absolutely-positioned div, so the text overlaps the footer below 1600px, while A uses normal document flow."
Use the "this task is broken" escape hatch with judgment. Distinguish a task that genuinely cannot be completed from one that is merely hard.
Qualifications
Must-Have
3–8 years of professional web development experience in frontend or full-stack work.




Fluency across web eras, including legacy layouts like used for layout.
Command of hand-written HTML and CSS : semantic markup, flexbox, grid, media queries, and legacy float- and table-based layouts.
Browser DevTools as muscle memory.
Command-line comfort: unzipping an archive, standing up a static local server, and untangling a broken image reference.
Enough JavaScript to read a page's scripts and understand their DOM impact.
Professional written English for task justification.
Preferred
Prior RLHF , preference-labeling, model-evaluation, or structured code-review work.
Pixel-perfect design-to-code experience.
Accessibility expertise ( ARIA , semantic landmarks, heading hierarchy).
Familiarity with how LLMs fail at code generation.
Web scraping, archiving, or DOM-parsing background.
More than one completed Mercor project and availability in contiguous multi-hour blocks.
Application Process (Takes 20–30 mins to complete)
Upload resume
AI interview based on your resume
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Resources & Support
For details about the interview process and platform information, please check: https://talent.docs.mercor.com/welcome
For any help or support, reach out to: [email protected]
PS: Our team reviews applications daily. Please complete your AI interview and application steps to be considered for this opportunity.

📌 Frontend Code Evaluation Specialist (Ciudad de México)
🏢 Mercor
📍 Ciudad de México