Startup hiring is a fuzzy science at best. Apart from abilities it's a lot about what impression you make in the first few interactions with the team.
Before talking to the team, invest a good amount of time researching on the space the company is operating in. The problem space, adjacencies, incumbents in that space and their offering, know what's unique about the company and the product. Learn terminology. Understand key metrics. Go overboard. Know everything you can beforehand. Use this knowledge in your interactions with the team. Ask pointed questions. Recognise and complement if there is something clever about their positioning and the business advantage they have because of it.
You want to leave them with the impression that the guy is not just experienced but is sharp and understands what we are doing here.