DARPA doesn’t always stick to the ‘ideal’ APRA framework that I and others normally describe. DARPA programs can also look much more like a normal government R&D program - the military needs something so they tell the director to start a program around the idea. The director finds a program manager to execute on the idea. The program manager ends up looking much more like a project manager with very little input over the direction of the program at all. This way of doing things seems relatively rare and happens more in the military-systems prototype focused offices (TTO and DSO) than elsewhere
While DARPA has gotten some exceptions to broad government rules around hiring and how they can spend money (DARPA is incredibly flexible with who it hires to be program managers) DARPA is still subject to many ‘stupid government rules.’ They aren’t allowed to use Google docs or zoom regardless of how un-sensitive information is. Modern DARPA still requires grants to go through the official government grant application website. The grant application page is almost tear-inducing. Cold contacting a PM requires filling out a web form that then sends a note to the PM’s secretary who may or may not set up a time for you to talk to the PM a month out. I can only imagine this friction reduces the number of serendipitous ideas PM’s receive. (Small amounts of friction can have large effects) IARPA puts emails directly on the website so ‘it’s to prevent too many emails’ is not a valid excuse. From personal experience, at least some DARPA employees treat the weekend as sacred no-work-email time regardless of urgency - a behavior I associate with large bureaucracies where people have little stake in outcomes.
At the end of the day Politics still sneaks in. The biggest example of this were the changes in 1972 thanks to shifting views on the military as a consequence of Vietnam. Throughout DARPA’s history, new presidents have occasionally replaced the DARPA director and Starting in 2001, DARPA directors began to sync up with presidential administrations.