David Cancel has some interesting thoughts on how they split up product management and tech team responsibilities in How we transformed HubSpot into a Product Driven Company. I really liked this part about embedded designers:

While we kept the core technical team tight, they were bolstered by the presence of embedded product marketers and UX designers all fixed on the same problem and solution. Designers and UX researchers informed the product teams from the point of mockups, through testing phases, to the ultimate release and support the product. […] The upshot here is that product teams become wholly self-sufficient organisms. They are small enough to retain customer focus but still have the skilled resources they needed to design, test and market the solutions they developed.

That post led me to Jeremy Crane’s What does a Product Manager do at HubSpot, which goes into more detail on the PM/Tech team split:

Every product team’s job is, essentially, to solve problems for their customers. Solving problems involves two key components: (1) Understanding the problem, and (2) creating the solution. At HubSpot the product manager owns the “problem” and the technical team owns the “solution.”  The “problem” is defined by whatever is likely to produce the greatest value to the customer and the business at large within the area of influence. The “problem” is both long-term and short-term in scope. It addresses the immediate challenges that the customer is experiencing, while still keeping an eye the longer-term vision of the product as a whole.