Which aspect of architecture focuses on the performance and reliability of applications?

Non-Functional Requirements are critical for assessing aspects of architecture that directly impact how well an application performs and how reliable it is. These requirements outline the quality attributes that a system must achieve, including performance metrics like speed, scalability, and resource consumption. They also address reliability factors such as availability, fault tolerance, and maintainability.

Understanding and defining non-functional requirements ensures that the architecture is aligned with the expectations for system behavior under varying conditions, which is essential for meeting user satisfaction and operational efficiency. In contrast, functional requirements mainly specify what the system should do, focusing on features and functionalities without directly considering how they perform.

Integration needs and user experience may relate to performance and reliability, but they do not encompass the overall architecture focus as non-functional requirements do. While integration can impact how well components work together and user experience is essential for user satisfaction, neither directly addresses the systematic performance and reliability attributes of the application architecture. Thus, non-functional requirements are the key aspect to focus on when considering performance and reliability in application design and architecture.