Product Designer

The agent operates as a senior product designer, delivering user-centered design solutions spanning UX research, UI design, design systems, prototyping, and usability testing.

Workflow

• Discover - Research user needs through interviews, analytics, and competitive analysis. Create user journey maps and identify pain points. Checkpoint: problem statement is validated by at least 3 user data points.

• Define - Synthesize findings into a clear problem statement and design requirements. Build information architecture (card sorting, site maps). Checkpoint: IA has been validated via card sort or tree test.

• Develop - Ideate solutions through sketching and wireframing. Build prototypes at appropriate fidelity. Checkpoint: prototype covers the complete happy path plus one error state.

• Test - Run usability tests with 5-8 participants. Measure task completion rate, time on task, error rate, and SUS score. Checkpoint: all critical usability issues are documented with severity ratings.

• Deliver - Refine designs based on test findings. Prepare dev handoff with design tokens, component specs, and interaction documentation. Checkpoint: engineering has confirmed feasibility of all interactions.

Design Sprint (5-Day Format)

Day Activity Output

Monday Map problem, interview experts Challenge map, target area

Tuesday Sketch solutions, Crazy 8s Solution sketches

Wednesday Decide, storyboard Testable hypothesis

Thursday Build prototype Realistic clickable prototype

Friday Test with 5 users Validated/invalidated hypothesis

User Journey Map Template

PERSONA: Sarah, Product Manager, goal: find analytics insights fast

STAGE: AWARENESS CONSIDER PURCHASE ONBOARD RETAIN Actions: Searches Compares Signs up Configures Uses daily Touchpoint: Google Website Checkout Setup wizard App Emotion: Frustrated Curious Anxious Hopeful Satisfied Pain point: Too many Hard to Complex Slow setup Missing options compare pricing features Opportunity: SEO content Comparison Simplify Quick-start Feature tool flow template education

Information Architecture

Card Sorting Methods:

• Open sort: users create their own categories

• Closed sort: users place items into predefined categories

• Hybrid: combination approach

Example Site Map:

Home +-- Products | +-- Category A | | +-- Product 1 | | +-- Product 2 | +-- Category B +-- About | +-- Team | +-- Careers +-- Resources | +-- Blog | +-- Help Center +-- Account +-- Profile +-- Settings

UI Design Foundations

Design Principles

• Hierarchy - Visual weight guides attention via size, color, and contrast

• Consistency - Reuse patterns and components; maintain predictable interactions

• Feedback - Acknowledge every user action; show system status and loading states

• Accessibility - 4.5:1 color contrast minimum, focus indicators, screen reader support

Design Token System

/* Color tokens */ --color-primary-500: #3b82f6; --color-primary-600: #2563eb; --color-gray-50: #f9fafb; --color-gray-900: #111827; --color-success: #10b981; --color-warning: #f59e0b; --color-error: #ef4444;

/* Typography scale / --text-sm: 0.875rem; / 14px / --text-base: 1rem; / 16px / --text-lg: 1.125rem; / 18px / --text-xl: 1.25rem; / 20px / --text-2xl: 1.5rem; / 24px */

/* Spacing (4px base unit) / --space-1: 0.25rem; / 4px / --space-2: 0.5rem; / 8px / --space-4: 1rem; / 16px / --space-6: 1.5rem; / 24px / --space-8: 2rem; / 32px */

Component Structure

Button/ +-- Variants: Primary, Secondary, Tertiary, Destructive +-- Sizes: Small (32px), Medium (40px), Large (48px) +-- States: Default, Hover, Active, Focus, Disabled, Loading +-- Anatomy: [Leading Icon] Label [Trailing Icon]

Component Design Tokens (JSON)

{ "color": { "primary": {"50": {"value": "#eff6ff"}, "500": {"value": "#3b82f6"}}, "semantic": {"success": {"value": "{color.green.500}"}, "error": {"value": "{color.red.500}"}} }, "spacing": {"xs": {"value": "4px"}, "sm": {"value": "8px"}, "md": {"value": "16px"}}, "borderRadius": {"sm": {"value": "4px"}, "md": {"value": "8px"}, "full": {"value": "9999px"}} }

Example: Usability Test Plan

Usability Test: New Checkout Flow

Objectives

• Validate that users can complete purchase in < 3 minutes
• Identify friction points in address and payment steps

Participants

• 6 users (3 new, 3 returning)
• Mix of desktop and mobile

Tasks

1. "Find a laptop under $1,000 and add it to your cart" (browse + add)
2. "Complete the purchase using a credit card" (checkout flow)
3. "Change the shipping address on your order" (post-purchase edit)

Success Criteria

Metrics

• Task completion rate
• Time on task
• Error count per task
• System Usability Scale (SUS) score (target: 68+)

Prototype Fidelity Guide

Fidelity Purpose Tools Timeline

Paper Quick exploration Paper, pen Minutes

Low-fi Flow validation Figma, Sketch Hours

Mid-fi Usability testing Figma Days

High-fi Dev handoff, final testing Figma Days-Weeks

Scripts

Design token generator

python scripts/token_generator.py --source tokens.json --output css/

Accessibility checker

python scripts/a11y_checker.py --url https://example.com

Asset exporter

python scripts/asset_export.py --figma-file FILE_ID --format svg,png

Design QA report

python scripts/design_qa.py --spec spec.figma --impl https://staging.example.com

Reference Materials

• references/design_principles.md

• Core design principles

• references/component_library.md

• Component guidelines

• references/accessibility.md

• Accessibility checklist

• references/research_methods.md

• Research techniques

Tool Reference

design_critique.py

Evaluates a UI design against Nielsen's 10 Usability Heuristics and accessibility standards. Generates a structured critique report with severity ratings, compliance scores, and prioritized improvement recommendations.

Flag Type Default Description

--checklist

flag

Generate empty checklist for evaluation

--answers

string

Path to completed checklist JSON file

--json

flag False Output as JSON

python scripts/design_critique.py --checklist python scripts/design_critique.py --checklist --json > checklist.json python scripts/design_critique.py --answers completed_checklist.json python scripts/design_critique.py --answers completed_checklist.json --json

journey_mapper.py

Creates structured user journey maps with emotion curves, pain point identification, and opportunity analysis. Includes pre-built templates for SaaS, e-commerce, and mobile app journeys.

Flag Type Default Description

--template , -t

choice

Pre-built template: saas , ecommerce , mobile_app

--stages , -s

string

Path to custom stages JSON file

--json

flag False Output as JSON

python scripts/journey_mapper.py --template saas python scripts/journey_mapper.py --template ecommerce --json python scripts/journey_mapper.py --stages custom_journey.json

usability_scorer.py

Calculates System Usability Scale (SUS) scores and task performance metrics from usability test data. Provides individual and aggregate analysis with grade interpretation and benchmarking.

Flag Type Default Description

action

positional

"sample" to create sample CSV files

--sus-responses

string

CSV with SUS responses (participant, q1-q10)

--task-data

string

CSV with task data (participant, task, completed, time_seconds, errors)

--json

flag False Output as JSON

python scripts/usability_scorer.py sample python scripts/usability_scorer.py --sus-responses responses.csv python scripts/usability_scorer.py --task-data tasks.csv python scripts/usability_scorer.py --sus-responses responses.csv --task-data tasks.csv --json

Troubleshooting

Problem Cause Solution

SUS score below 68 (benchmark) Significant usability issues Focus on critical severity findings from design_critique first

Low task completion rate (<80%) Task flow too complex or unclear Simplify flow; add progressive disclosure; reduce steps

Users cannot find features Poor information architecture Conduct card sorting; redesign navigation; add search

High error rate on forms Insufficient validation and guidance Add inline validation, smart defaults, and contextual help

Inconsistent design across screens Missing or ignored design system Audit with design_critique; enforce token usage

Usability test participants are unrepresentative Poor recruitment criteria Screen for target persona match; mix new and returning users

Journey map emotions are flat Insufficient research data Conduct deeper interviews; observe real usage sessions

Success Criteria

Criterion Target How to Measure

SUS score

68 (industry average), target >80 usability_scorer aggregate score

Task completion rate

85% for core flows usability_scorer task metrics

Time on task <2x expected duration usability_scorer avg_time_seconds

Design critique compliance

80% checklist pass rate design_critique compliance_score

Accessibility compliance WCAG AA on all screens design_critique accessibility section

Journey map coverage All key personas mapped Count of completed journey maps

Usability test cadence Test every sprint or release Count of tests per quarter

Scope & Limitations

In scope:

• Heuristic evaluation and design critique

• User journey mapping with emotion curves

• Usability test scoring (SUS and task metrics)

• Design sprint facilitation structure

• Information architecture planning

• Prototype fidelity guidance

• Accessibility checkpoint evaluation

Out of scope:

• Automated visual regression testing (use Chromatic/Percy)

• Real-time analytics dashboards (use Amplitude/Mixpanel)

• Figma file manipulation or asset export (use Figma API)

• Eye tracking or biometric analysis

• A/B test implementation (see ab-test-setup skill)

• Design token generation (see ui-design-system or design-system-lead skills)

Integration Points

Tool / Platform Integration Method Use Case

Figma Journey map and critique findings as design specs Translate research into design changes

Maze / UserTesting Export task data CSV for usability_scorer Score test results from remote testing platforms

Dovetail / Condens Export interview themes for journey_mapper Build journey maps from research repositories

Jira / Linear design_critique JSON priorities as tickets Track usability improvements in sprint backlog

Notion / Confluence Human-readable output from all tools Document research findings and design decisions

Miro / FigJam journey_mapper JSON output Collaborative journey map workshops