Various cognitive theories indicate how the brain and technology have interacted with each other in an iterative and progressive manner to shape human cognition. Technologies are cultural tools that emerged as a human response to address specific needs. These technologies have allowed us to overcome various ecological, social, and cultural challenges that have impacted the phylogenetic development of higher cognitive abilities that have elevated Homo sapiens above other species. In the digital age, technologies such as the internet, smartphones, and the various software applications that derive from them play a fundamental role in how we relate to ourselves and society. Understanding how humans interact with these technologies, and the effect they have on altering brain architecture, is essential for designing and developing better tools. This chapter summarizes the key findings that explain the consequences of using these technologies on our development and how behavior, through these means, has given rise to digital behavior. Digital behavior is the compendium of interactions and their consequences that occur on the individual when using a digital service. The design of digital behaviors can be described as a new sub-field of Human Factors and Engineering Psychology, with habit formation and need satisfaction serving as the main epistemological core of digital behavior design. The design of digital behaviors is a necessary discipline that can enhance user engagement with these technologies by improving cognitive ergonomics, thereby more effectively addressing the needs that users bring to these types of services.