K Sabeel Rahman-The informational, economic, and political influence of the dominant tech platforms — Google, Facebook, and Amazon in particular — has become a central topic of debate. K. Sabeel Rahman argues that these firms are best understood as the core infrastructure of our 21st century economy and public sphere. The infrastructural power of these firms raises a range of policy questions. What exactly about these firms (e.g., their accumulation of data, their gatekeeping functions, their control over vital public and economic functions like retail delivery or online speech) is “infrastructural?” How should these infrastructural functions be governed and regulated, in light of both their economic and political influence?