The interview process was very thorough and involved various people I would be commonly be interacting with as well as a few technical challenges along the way. It is key for you to be passionate about the work the organization is doing, must be a work culture fit!
My advice for you:
Do your research on the company, research any and all Planet Labs related things. LinkedIn is your friend, identify people you could potentially working side-by-side with. Be confident, if you aren't fake it. Know how they have progressed and have an idea where they could be going. Be prepared for a technical challenge and manage your time accordingly. Last and most important, have a purpose for why you have chosen your career and relate it to what Planet Labs is doing.