If you want to change the world, it's not enough to startup -- you have to turn an idea into a company worth billions that keeps growing fast. In other words, it's not enough to startup, you have to scaleup.

I recently interviewed two Harvard Business School professors -- Jeffrey Rayport, HBS Senior Lecturer and Shikhar Ghosh, HBS Professor of Management Practice -- who shared their eight keys to changing the world..

1. Combine vision with detail

To find the next Bezos, you should look for a leader who is great at both vision and "the weeds." As Rayport said in a June 8 interview, "To spot the next Bezos, look for someone who is near- and far-sighted. He is able to focus on people, culture, friction, and details without losing sight of the mission."

What makes Bezos exceptional is that he is both -- rather than one or the other. "Usually, you either have someone who is good at the weeds or great at the vision -- a pied piper who people love to follow. The visionaries need a chief operating officer. Arguably after 10 years with Eric Schmidt as chair, Larry Page grew into the job, Mark Zuckerberg has Sheryl Sandberg. Bezos -- when I met him in the 1990s -- was both high concept and could go deep into the details," he explained.

2. Never stop learning voraciously

Another important trait that distinguishes what my book, Startup Cities, called marathoners -- leaders who can take an idea and build it into a multi-billion dollar public company -- is the ability to keep learning. As Rayport noted, "People like Bezos are voracious learners who change when they are exposed to new information. We extoll the virtues of learning, but most people stop learning voraciously at their core once they leave school."

3. Change culture as your company grows

Such leaders are also able to scale their cultures. This means that as their companies grow, they can create and manage the organizational inputs that produce behavior in their people that's consistent with the company's values.

Rayport explained:

Culture is not about being nostalgic about the good old days when there were no formal meetings and no HR department. It's not one and done. As a company goes from 10 to 100 to 200 to 1,000 people, you might have the same values -- such as integrity, transparency, teamwork, accountability, passion, and energy. But those are all outputs. For the culture to scale, you need to know what management levers you can pull to get people to act according to those values. For example, Bezos has physical, tangible rituals -- such as leaving an empty chair at meetings for the customer and asking everyone to read a six page memo prepared for a meeting before it begins.

4. Match Strategy to Your Company's Growth Stage 

It's smart to look at the stages as relating to the different funding rounds -- e.g., seed, Series A, B, and so on. The first stage is before you have product/market fit at which point you are trying to raise seed capital from angel investors. Once you have product/market fit -- which means customers are willing to pay for your product and you can scale up with profitable unit economics -- you should capitalize to get big fast.

5. Adapt to the Power of Three

Ghosh has a power of three rule. As he explained in a June 7 interview, "At each power of three -- the number of people in the organization (30, 90, 270, 810) -- everything changes. When everyone in the company can be fed with two pizzas, the leader can look at all the coders and get things done. But as you scale, you add layers, you have division of labor, you specialize -- and the people you started with can't have the same kind of direct contact with the leader as they used to."

6. Manage the Tension Between Process and Culture

This creates a battle between culture and process. According to Ghosh, "Managers come into the company and they want to create formal processes. But process works for activities like accounting and not so well for creative work where it is better to set goals and let people figure out how to get there. Size often demand more formal process which is at odds with the history and mythology of the company -- such as the idea that everyone worked 24 hours a day for a week before the end of a quarter in order to meet goals."

7. Let Go to Go Further

When a company gets bigger, the leader has to accept that new talent will do things differently -- and make mistakes. But if the leader does not let go, the company will not be able to scale. As Ghosh said, "If the founder continues to be the chief problem solver, the people he hires to run -- say an operation in a new city -- will never become effective leaders. Instead, the founder should accept that as you create a new subgroup, there's a V-curve. You will initially get less efficient. But after the subgroup makes mistakes and learns, it becomes more efficient and reaches a limit. If you intervene, you do worse."

8. Make Common Purpose Stronger Than Chaos 

As a company scales the role of the leader is to make sure that the centipedal forces are stronger than the centrifugal ones. "As a company grows, it gets more specialized. Specific business functions want to optimize themselves which pulls the company apart. The only way to keep functions line engineering, finance, sales and so on together is to continuously remind everyone of the company's purpose, mission, values and desired behaviors."

If you meet someone who can do all these things well, you are probably looking at the next Jeff Bezos.