Platforms have become an important way to organize work. However, many researchers and unions have pointed out the limitations of platforms, such as Uber and Mechanical Turk, for workers. In this talk, we begin by presenting problems with dominant ridehail platforms (e.g. Uber and Lyft) for workers. We then explain the barriers to innovation faced by workers developing a platform that serves their needs. This work draws on our recent publication ""Hostile Ecologies: Navigating the Barriers to Community-Led Innovation"" from ACM CSCW 2022. We then show how our UCSD research team worked with United Taxi Workers San Diego to overcome these barriers through design, data policy analysis, and software engineering assistance. The result is our labor union ridehail platform RideUnited. We conclude with lessons on how human-computer interaction shifts when workers and worker organizations are placed at the center of systems development.