Ruby On Rails Junior+/Middle Developer

Itransition; España; Remote; EUR 91,000 - 130,000; Part time

Job summary

Mercor is seeking a Web Development Expert for a fully remote contract role priced up to $90/hr. You will render a reference page and two candidate replications at 1920×1080 and judge which is closer, across viewports.

You will compare fidelity, typography, spacing, color, borders, and assets; read source code, grade construction quality, and test responsiveness, noting defects like nav collapse. The role requires 3–8 years of web development, HTML/CSS mastery, and strong written English to

Qualifications

• 3–8 years of professional web development experience.
• Fluency across web eras and legacy layouts.
• Hands-on HTML and CSS with semantic markup, flexbox, grid, and media queries.
• Proficient in browser DevTools.
• Comfort with the command line and local server setup.
• Enough JavaScript to read scripts and understand DOM impact.
• Proficient technical English for task justification.
• Nice-to-have: RLHF, pixel-perfect design-to-code, ARIA accessibility.

Responsibilities

• Render a reference page and two replications at 1920×1080 and judge closeness.
• Diff visual fidelity: box model, typography, color, borders, images.
• Read source and grade construction quality; distinguish truly correct from merely looking correct.
• Test responsiveness and identify defects like nav collapse across viewports.
• Provide evidence-cited justifications for every preference.
• Use the "escape hatch" to flag when a task is truly unfeasible.

Skills

Frontend development

HTML/CSS

JavaScript basics

Browser DevTools

Command-line skills

Semantic HTML

English writing

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.

Application Process (Takes 20–30 mins to complete)

• Upload resume
• AI interview based on your resume
• Submit form

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.