I love how nobody answers this. It means dev and sales are the critical ones.<p>UX/CX is often a huge one. People think this is just hiring a designer. Nope. The person in charge has to understand the customer experience end to end and be able to modify it very quickly based on new information.<p>This is usually the CEO, who has access to all the information from marketing, sales, engineering, analytics, investors, etc. Especially for the startup level it's often the CEO who understands the problem and the users.<p>There's also a lot of design decisions involved in UX. Bounce rate is almost entirely dependent on UX.<p>It can't be outsourced either. You can have, say, a TV UX expert advise you in TV use cases or a e-commerce UX expert advise on ecommerce UX. The UX consultants have been the most expensive so far.<p>But past a point, only the people who deeply understand this company's product and the user problems can properly do UX and CX.