Most valuable biz skills to a Series B startup - I will not promote

I’m exploring opportunities at Series B startups and want to understand which skills are the most valuable at this stage, particularly in growth, marketing, and sales. From what I’ve seen, Series B startups typically have some product-market fit and initial traction, but they’re focused on scaling efficiently. For those who have worked at this stage: - Which specific skills or experiences have been the most impactful? - How does the skill mix shift from seed to Series A to Series B? - What do founders/hiring managers value most in non-technical roles at this stage? Would love to hear from those with firsthand experience, whether as operators, investors, or founders.