While I don't think we can get a lost of what every individual Scratch Team member does, a few roles I know they have:

Administration (top-level positions that set the overall direction of the organization and are in charge of individual departments)
Management (similar to management at any other company)
Engineers (the people that write the code that makes everything work, includes frontend and backend engineers)
Moderation (the people who make sure that content is safe for all ages)