What is primarily tested during the final phase of a design sprint?

The final phase of a design sprint primarily focuses on user interactions with the prototypes. This stage is crucial as it allows the design team to gather feedback from real users by observing how they engage with the prototypes developed in earlier phases. By testing these prototypes, designers can assess usability, identify pain points, and understand user behavior in response to the design concepts.

This user feedback is instrumental in validating design decisions, refining the product, and ensuring that the solution effectively meets user needs and expectations. The insights gained from this phase can inform necessary adjustments before the product moves into further development or implementation.

In contrast, other options, such as the marketing strategy, financial feasibility, and aesthetics of the final design, while important in the overall design and business process, are not the primary focus during this critical testing phase. The energy during the final phase is centered around user experience, ensuring that the product functions as intended and resonates with users, which is key to its success.