UX Design definition
UX design (user experience design) is the process of designing products, such as websites, apps and services, so they are useful, usable and satisfying for the people who use them. It covers research into user needs, information architecture, user flows, wireframes, prototyping and usability testing, shaping how a product works and feels rather than only how it looks.
The UX design process
UX design moves between understanding problems and testing solutions. The UK Design Council's Double Diamond model, published in 2005, describes this as two rounds of widening and narrowing: discover and define the right problem, then develop and deliver the right solution. In practice the process is iterative, and good teams cycle through it many times as they learn.
- Research: interviews, analytics, support tickets and observation of real users.
- Define: personas, jobs to be done and clear problem statements.
- Ideate: sketch many possible solutions before choosing.
- Structure: information architecture, navigation and user flows.
- Wireframe and prototype: low- then high-fidelity versions, usually in Figma.
- Test: usability tests with representative users.
- Iterate and measure after launch.
UX design vs UI design
UX design covers the whole experience: whether the product solves the right problem, how tasks flow, what information appears where and how easy it is to recover from mistakes. UI design focuses on the visual and interactive layer: layout, typography, color, components and motion. A beautiful interface on a confusing flow still fails, and a smart flow with an unclear interface frustrates users. Many designers do both, but the disciplines require different skills.
Principles of good UX
Jakob Nielsen's ten usability heuristics, published in the 1990s, remain a widely used checklist. They include showing system status, matching users' language and expectations, giving users control and easy undo, staying consistent with conventions, preventing errors, favoring recognition over memorization, and providing helpful error messages. Good UX also reduces cognitive load by showing only what matters at each step.
Accessibility is part of UX, not an extra. Designing for keyboard users, screen readers, low vision and different abilities improves the experience for everyone, from people using a phone in bright sunlight to older users with less precise touch. It is also a legal requirement in many markets.
How to measure user experience
UX is measurable. Usability metrics include task success rate, time on task and error rate. The System Usability Scale gives a standard satisfaction score, and Google's HEART framework tracks happiness, engagement, adoption, retention and task success. Product analytics show funnel drop-offs, and qualitative feedback explains them.
Worked example: a fintech app's onboarding loses many users at the identity verification step. Usability tests reveal confusion about which document to upload and fear that the photo failed. The redesign adds examples, live camera guidance and clear progress feedback, and completion rises in the next release.
UX design tools
Figma is the standard tool for wireframes, interface design and prototypes, with FigJam for workshops and journey mapping. Maze and similar tools run remote unmoderated usability tests, while Hotjar and Microsoft Clarity show heatmaps and session recordings. Survey tools, analytics platforms and simple paper sketches complete the toolkit. Nexzem's UX team combines research, flows and prototypes with usability testing on real users before development begins.