Between the Great Recession and the COVID-19 pandemic, the U.S. technology industry increasingly shifted towards cities. Local governments pursuing innovation-led growth encouraged this shift, as exemplified by San Francisco, the spatial and symbolic urban home of the global technology industry. The commercial real estate market is central to understanding the city’s growth as a tech cluster between 2008 and 2020. Platform technology firms substantially contributed to employment growth and demand for office real estate in San Francisco during this period of rapid tech industry expansion. The city also exemplifies how the pandemic-led transition to remote work has profoundly changed the relationship between platform firms and urban space. In this paper, we use interviews and secondary sources to study tech-led office leasing and development activity in San Francisco. We identify neighborhood-level trajectories of path dependence, industrial conversion, failed revitalization, and frontier-making during the period of growth leading up to 2020. Digital platform companies exert significant economic and political influence over cities, but their control over urban space is also constrained by the historical, material, and economic realities of commercial real estate.