The PMM team at HackerOne reports in Marketing. PM's purpose in the universe is to build the right product by translating customer needs into products they can't live without. PMMs role is to translate these products into value propositions that move customers to action and help influence the product roadmap.
To establish credibility with a new team, the first step is understanding the team's need, laying out a vision for how you can best add value, and aligning around expectations. It is important to know the user, the market, and the product so that you can engage with the cross-functional team in a meaningful way from day one. With a clear set of objectives and foundational understanding of the space, you can quickly begin to make an impact on the team.