What makes a good UI design?
Written by
Passionate Designer & Founder
Good UI design doesn't generate rework, doesn't produce support tickets about confusion, and doesn't need a tooltip on every field to explain what the field does. Three things separate good UI from polished-but-broken UI: state coverage, system consistency, and load performance. Most design reviews evaluate visual quality. Almost none evaluate all three.
State coverage means every interactive element has a defined hover, focus, active, disabled, loading, and error state. A UI with 80% beautiful screens and 20% undefined states will generate more negative user signals than a visually average UI that is fully specified. This is the most common failure mode I see in products that have had "design work done" but still confuse users.
System consistency means components are reused, not recreated. A Figma file with 200 unique button variants is not a design system, it's a liability. In a properly built component library, a change to the primary button propagates to every screen in under 5 minutes. Without that, a rebrand or an A/B test becomes a 3-week manual update cycle. On the Montblanc digital project, we audited an inherited Figma file containing 47 visually similar but technically unique card components. Consolidating those to 6 variants with defined properties cut the UI update cycle for new campaigns from 4 days to half a day.
The performance factor most designers disclaim
Load performance is the UI factor that design teams own but often disclaim. Image weight, animation complexity, and font loading strategy are UI decisions. A hero section that takes 4.2 seconds to render on a 4G mobile connection is a failed UI, regardless of how it looks in Figma. Google's Core Web Vitals penalize Largest Contentful Paint scores above 2.5 seconds. That threshold is partly a UI responsibility.
The part almost no one names: the best UI matches the cognitive load of its user at that moment. A dashboard for a logistics operations manager running 12 simultaneous shipments needs dense information display, not the minimalist card layout that wins design awards. A consumer onboarding flow for a fintech app targeting first-time investors needs the opposite. Good UI reads the user's context and makes a deliberate choice, rather than defaulting to whatever design trend is fashionable this quarter.
Across the SaaS products we've worked on under retainer, products with fewer than 8 component variants in their core UI consistently outperform products with 40+ variants on NPS and support ticket volume. Simplicity isn't a visual style. It's a structural decision made at the system level, not screen by screen.
The checklist I run before any UI review: every interactive element has 6 defined states; every component in Figma is connected to a shared library, not copy-pasted; every screen has been reviewed at 375px mobile width; and the heaviest image asset on the page is under 150kb. If those four criteria are met, the UI is probably shippable. If any one fails, it will generate problems after launch. For teams thinking about where design fits into their production workflow, our notes on the design production partner model are worth reading. Book a 20-min intro if you want us to audit your current UI against these criteria. For the full guide, read our ui overview.
