In this article, we investigate how Big Tech companies have used the novel coronavirus disease pandemic to increase their social, political, infrastructural, and epistemic power. We focus on four companies that were outspoken in their efforts to combat the virus: Alphabet (also known as Google), Apple, Facebook, and Amazon (GAFA). During the crisis, these companies evolved as adaptive entities that responded to the state of emergency by promptly rolling out various technological solutions, exemplifying what we call 'pandemic solutionism', that is, the belief in the potential to solve the complex virological crisis of COVID-19 through the integration of digital tools. We identify the activities of GAFA in pandemic solutionism in five key areas that can be defined as the dominant realms of Big Tech's involvement: (1) mapping COVID-19, (2) researching (3) tracing (4) treating and (5) managing In this context, we provide the first comprehensive overview of Big Tech's multifaceted engagement in researching COVID-19 based on wearable technologies, which have been actively promoted as potentially beneficial tools for detecting the coronavirus since the beginning of the crisis. Aditionally, through a critical mapping of the multiple activities of selected Big Tech players during the pandemic, it becomes evident how unexpected societal disruptions can lead to the increased dominance by these players. As we demonstrate, Big Tech companies have been able to present themselves as saviours capable of acting more promptly than the state, pushing pandemic solutionism and taking up tasks without being burdened by democratic deliberations. In doing so, they have manifested their infrastructural power, which frequently (such as with contact tracing) establishes the normative framework in which political and social actions take place.