UI/UX Design Expert - Evaluator

Mercor; Greater London; On-site; GBP 65,000 - 90,000; Full time

Job summary

Mercor partners with a leading AI research organization to define what excellent digital product design looks like. You will craft task-specific grading criteria and rigorously score samples with well-reasoned written justifications.

The role emphasizes evidence-based judgment, reproducible scoring, and iterative feedback from senior reviewers to ensure designs meet real user needs in dashboards, portals, and onboarding flows.

Qualifications

• 5+ years of professional experience in product design, UI/UX, or design systems for real digital products.
• Experience at leading digital-product and UX studios, in-house product-design teams, or e-commerce portals with sophisticated dashboards.
• Tracks: Product/UI/Design Systems Designer, UX Lead, UX Writer/Content Designer, or digital Product/Business Analyst.
• Deep fluency in interaction/visual design, design systems, responsive layouts, end-to-end product flows, prototyping and production handoff in Figma.
• Exceptional written communication and the ability to explain why a piece of work meets or misses the bar for a real product.

Responsibilities

• Design precise, task-specific grading criteria for real-world digital product and UX deliverables (design systems and component libraries, responsive UI layouts and dashboards, end-to-end product flows).
• Score AI-generated and human work samples against those criteria, with detailed written justifications for every score.
• Apply consistent, evidence-based judgment so scores are reproducible and defensible.
• Incorporate structured feedback from senior reviewers and iterate quickly on your work.

Skills

Product design

UI/UX

Design systems

Figma

Written communication

Detail-oriented

Tools

Figma

Job description

1. Role Overview

Mercor is partnering with a leading AI research organization to engage experienced UI/UX and product designers for a project focused on evaluating how well AI systems perform real-world digital product design work. Rather than producing deliverables yourself, you will define what excellent work looks like: designing task-specific grading criteria and scoring completed work samples with rigorous, well-reasoned written justifications.

2. Key Responsibilities

• Design precise, task-specific grading criteria for real-world digital product and UX deliverables (design systems and component libraries, responsive UI layouts and dashboards, end-to-end product flows such as onboarding, checkout, and booking, logged-in customer portals, UX writing and product content, and design-to-engineering/production handoff)


• Score AI-generated and human work samples against those criteria, with detailed written justifications for every score


• Apply consistent, evidence-based judgment so that scores are reproducible and defensible


• Incorporate structured feedback from senior reviewers and iterate quickly on your work

3. Ideal Qualifications

• 5+ years of professional experience in product design, UI/UX, or design systems for real digital products (not brand or marketing sites)


• Background at leading digital-product and UX studios, in-house product-design teams at major product-led companies, or e-commerce and marketplace companies with sophisticated customer portals and dashboards


• Experience across one or more relevant tracks: Product / UI / Design Systems Designer, UX Lead, UX Writer / Content Designer, or digital Product / Business Analyst


• Deep fluency in the day-to-day craft: interaction and visual design, design systems, responsive layouts, end-to-end product flows, prototyping and production handoff in Figma, and articulating critique the way a design or UX lead would in a review


• Exceptionally strong written communication, with the ability to explain exactly why a piece of work does or does not meet the bar for a real product and its users


• Detail-oriented, consistent, and comfortable having your judgment reviewed and calibrated against peers


• Prior experience with AI training, evaluation, or human-data projects is a strong plus