What roles do you hire for when building a growth team?

The areas I index the most when hiring someone:

• Partial - Do they fall in love with their own ideas? If so, then I don't believe they will be a strong Growth PM. Given so many experiments fail, you want someone who is focused on answering questions about the user and the science of it all.
• Analytical - They don't have to be a statistician, but they need to understand how to read the data and extrapolate user behavior from it
• Collaborative - This is probably the most important part. A person shouldn't be hired based on their ability to generate good ideas. Even if they do a great job at the beginning, they'll run out eventually. A great growth team leans on their xfn partners to help come up with good ideas. Also when you involve them, you end up with a happier team
• Logical - There's a reason why we do everything. Every change is intentional and has a further reason behind it. The ideal candidate is able to understand the decisions they're making and explain why they're doing it with rational data.

The first question I ask is "what skillset does the team need?". And then I figure out the roles.

I would always start by what skills for the team, rather than specific roles. If you have a sales person that is doing the job of a growth PM, then use this person rather than hire specifically a dedicated PM.