Avoid the Costly Mistake of Assembling the Wrong Leadership Team Make the leadership team transition from founder-led to a seasoned mix of diverse professionals. Opinions expressed by Entrepreneur contributors are their own. In the early days of building a start-up, there are several things that people tell you to focus your time and attention on. You need to have a strong business plan, an addressable market, an understanding of customer personas, product-market fit, etc. And while all of these things are key aspects of ensuring the short and long-term success of a start-up, there’s a less-discussed aspect that holds just as much, if not more, bearing on whether your business is going to be a success.