Fullstack Developer (.Net)

Nextlane; La Coruña; Remote; EUR 74,000 - 111,000; Full time

Job summary

Mercor is seeking a Web Development Expert to deliver pixel-perfect frontend work in a fully remote capacity. You will evaluate reference pages, craft replicas, and assess DOM impact across modern and legacy layouts.

The role emphasizes semantic HTML, CSS mastery, and robust JS reading to justify design choices. You will provide evidence-based explanations for recommendations and ensure responsive behavior at multiple viewports.

Qualifications

• 3–8 years of professional web development experience in frontend or full-stack.
• Fluency with legacy and modern layouts, including semantic markup.
• Proficient in hand-written HTML and CSS with responsive techniques.
• Strong knowledge of DevTools and debugging.
• Comfort with the command line and local server setup.
• Able to read and understand JavaScript to assess DOM impact.
• Professional written English for task justification.

Responsibilities

• Render a reference page and two candidate replications at 1920×1080 and judge closeness.
• Diff visual fidelity including typography, spacing, colors, borders, and assets.
• Read source of attempts and grade construction quality with evidence.
• Test responsiveness across breakpoints and identify defects.
• Provide evidence-based justifications for preferences.
• Consider edge cases and when task cannot be completed.

Skills

Frontend development

HTML

CSS

JavaScript basics

DevTools

Command line

English writing

Tools

Chrome DevTools

Static server

Job description

Web Development Expert - Fully Remote | Upto $90/hr

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.

Resources & Support

• For details about the interview process and platform information, please check:
• For any help or support, reach out to:

PS: Our team reviews applications daily. Please complete your AI interview and application steps to be considered for this opportunity.