Do you have someone who has the skills to do “outside the building” activities like interviewing customers, running usability tests, and getting user validation/feedback?
It's crucial that someone on the team is assigned to be the owner of the problem team. The problem team will properly validate the problem, your solution, and then the first version of your product (MVP - minimum viable product). Validating the problem and then the solution will verify that you are building a product that people want.
The truth is that most startups fail not because they cannot build the product that they envision, but because they've built a product and features that nobody wants.