Shay Ben-Barak (@ShayUXD) is a freelance experience strategist and senior usability expert. For the last 15 years he is leading projects from the early inventive stages of understanding the users' needs, throughout the process of concept design, to the detailed interaction design and visual design. He is experienced with mobile devices, legacy applications and web applications, and he was involved with development of consumers apps as well as complex systems (e.g. financial, medical, ERP and C4I systems) for professionals. Shay is also a UX mentor at the Google Campus TLV which is a pro bono publico activity of mentoring startups and entrepreneurs in their initial steps towards their very first UX prototype. Shay owns a master's degree (M.Sc.) in cognitive science from the Technion and his master thesis about Mental Models was published in chapter 5 in this book.