A UI/UX designer for web and mobile is responsible for creating user-centric designs for digital products such as websites, mobile apps, and software. They use their knowledge of design principles, human psychology, and user behavior to create interfaces that are intuitive, visually appealing, and easy to use.

The UI/UX designer works closely with developers, stakeholders, and other designers to ensure that the design meets the needs of the user and the client. They start with research and analysis to understand user needs and expectations, and then use this information to develop wireframes, prototypes, and final designs.

In addition to creating the visual design, the UI/UX designer is also responsible for ensuring a smooth and consistent user experience across all platforms and devices. They must consider factors such as accessibility, navigation, and performance when creating the design.

Overall, a skilled UI/UX designer for web and mobile understands the importance of user-centered design and is able to create designs that are both aesthetically pleasing and functional. They stay up-to-date on the latest design trends and technologies and are able to work collaboratively with other members of the design and development team to create a seamless user experience.