Once you are able to achieve some real "traction" with your business (paying customers, revenue stream), it may seem the time to relax a bit, but in fact this is the point where many founders start to flounder. All the skills and instincts you needed to get to this level can actually start working against you, and you can fail to scale.
Investors often say that successfully navigating the early stages of a startup requires lots of street smarts, guts and luck. For successful scaling of the business, there has to be a transition to "executive" mode in the more traditional business sense. Certain behaviors between these two modes are incompatible, and can cause real problems.
Way back in 2002, John Hamm published some early work on this subject in "Why Entrepreneurs Don't Scale" in the Harvard Business Review. Here is my interpretation of that work, incorporating my personal experience, identifying some strengths of an entrepreneur during early startup stages which can become a problem for scaling:
Perseverance. This is generally a required quality for a successful entrepreneur, but it can turn into an unhealthy stubbornness during the scaling stage. The key is to make decisions from data and feedback, once your business has real customers and real products. Trusting your gut at this stage isn't good enough.
Absolute control. During the early stages, you are the company, processes are not documented, you don't have much help, so you need a fanatical attention to detail. To scale the business, you have to find people who can do the tasks, and delegate appropriately. Control freaks are doomed to failure.
Individual loyalty. Most founders form very close relationships with the small team that gets the startup off the ground, and that is important. Scaling requires that you expand the team, probably with people you haven't known. You also have to deal with the inevitable personnel challenges, even within the original team. Total loyalty can be toxic.
Isolated and insulated. Working in isolation is fine during the creative phase of the startup, where the founder is often the designer and architect, as well as the builder. Now this same individual has to step into the spotlight, and meet with customers, analysts, and investors. Insulation from the real world will not work during scaling.
Tactical versus strategic. Early stage startup founders have to think tactically. Even business school courses don't teach you to operate strategically, deal with people objectively, and create loyalty within a diverse workforce. These are areas where past stumbles are the best teachers. Investors don't want to fund your stumbles.
Every founder moving into the executive role has to step back and take a hard look at what works, and what doesn't work. The best ones can do that, and they adapt. Investors and advisors see this as a critical part of their role, and often are the "bad guys" who ask the founder to step aside, while they bring in a "more experienced" CEO to take over the helm.
Unfortunately, some founders won't adapt, and won't step aside. Even if they are pushed out, they can cause terminal damage to the business by negative versions of their strengths, now seen as stubbornness, unwillingness to give up control, testing loyalty, and hiding from reality.
Thus my best recommendation, if you want to scale and to survive, is to open up and work closely with an "outsider" that you trust, such as a respected board member, a coach, a mentor or an investor. The key is to expedite your learning, and take deliberate steps to confront your shortcomings. That way, you will become the leader your company needs, learn to stop floundering, and begin to fly.