Here's the story of a company and a founder that has been told many times.

A company has become huge. They've had overwhelming success. But they've become slow and bureaucratic, and innovation has slowed. It's become a boring place to work.

A star employee, let's call her Jane, sees a clear opportunity to improve the company's situation. She has some great ideas on how to breathe fresh growth into the company. Jane's ideas are ignored. Nobody listens to her.

But Jane can't get her ideas out of her head. She needs to pursue her idea. So she leaves the company, raises some money, and builds a product and a company around her idea.

In order to succeed, Jane needs to build a great team. Because there are so many challenges in launching a new company that will beat the incumbents, she needs a team of superstars. She needs to hire people that are amazing. People that are able to run through walls. People that are irreplaceable.

So Jane builds a team full of stars.

And it works. The team of stars is able to take market share and grow rapidly. They have lots of success. They scale and have hundreds of employees. Soon they have thousands of employees.

Now, Jane's burden isn't to disrupt a business or industry; her burden is to protect what she's built. At this point, Jane needs to hire people that are replaceable. If someone is irreplaceable, that's a problem. She needs to build systems and processes and support around her employees so that no single employee is critical to the company's success.

Jane's company has gone from requiring people that are irreplaceable to requiring people that are replaceable. And the cycle continues…

As startups grow, they shift from breaking new ground to protecting their ground. This shift happens gradually and impacts some functions and roles before others. It's very difficult for companies to make this shift. It requires adaptable people, different people, and lots of process building. And you obviously will always need lynchpin employees in some roles.

The irreplaceable vs. replaceable concept is a simple framework for how to think about company building in the later stages of growth.