The design of successful assistive technologies requires careful personalization for individual users, as well as rapid, low cost cycles for product development and testing. My research brings two modern software engineering models to meet these challenges: Personal and Contextual Requirements Engineering (PC-RE) and Agile Software Development. We adapt these models to the assistive mobile navigation domain for the blind. This dissertation demonstrates that a Virtual Environment testing can significantly reduce testing time, yield meaningful testing results by fully controlling environmental variables, alleviate logistical and safety problems, and serve as an ideal platform for deep personalization. We developed a narrative NAvigation Virtual Environment (NAVE) and compared blind subjects’ performance and behavior in wayfinding tasks with tactile maps under field testing versus testing in NAVE. Our experiments showed positive results to support our hypothesis that virtual environments can be useful in replacing field testing for personalized assistive technologies in agile development.