Usability refers to the ease of use and effectiveness with which a user can interact with a product or system to achieve a specific goal. Key components include learnability, efficiency, memorability, error rate, and user satisfaction.

In a previous role, I conducted usability testing on a web application and discovered that users struggled with the navigation. By simplifying the navigation structure and adding clear labels, we reduced user confusion and increased task completion rates by 25%.

I employ a variety of tools and methods, including user interviews, A/B testing, eye-tracking studies, heatmaps, and software like UsabilityHub and Optimal Workshop. The choice of tool depends on the project requirements and which aspects of usability we aim to evaluate.

I prioritize usability issues based on their impact on user experience and business objectives. High-impact issues that affect key user tasks or conversions take priority. I also consider the frequency of occurrence and the resources required to address each issue.

Ensuring accessibility involves following established guidelines like WCAG, conducting accessibility audits, and incorporating features such as keyboard navigation, alternative text for images, and adjustable text sizes. It's crucial to design inclusively from the beginning and involve users with disabilities in testing.

User feedback is invaluable in usability engineering as it provides direct insights into user experiences and perceptions. It helps identify pain points, validates design decisions, and guides iterative improvements. I use feedback mechanisms like surveys, feedback forms, and direct user testing sessions to gather this information.