As part of a research program on mastery learning, inspired by the benefits of Computer-Based Testing reported by the University of Illinois at Urbana-Champaign, in Fall 2023 we ran a pilot of such a facility ourselves. If the pilot succeeded, we intended to scale up and eventually serve the whole campus, not just one or two CS courses. Three years later, our CBTF operation is 20x larger and serving departments across campus; bootstrapping the initial effort led to important lessons—some evident only with long hindsight—from which we hope others might benefit. Our two main takeaways are as follows. First, even in a small pilot, avoid adopting processes that won’t scale, since student and faculty expectations are heavily influenced by the initial policies and procedures. Second, while various campus units typically “own” lab facilities, proctoring for students with disabilities, instructional software and hardware maintenance, room reservations, and so on, usually no one “owns” whole-course proctored exam administration. You will have to create new administrative processes, disrupt existing ones, correct mistaken faculty assumptions, and coordinate across nonporous administrative boundaries.