John Sculley is one of the most polarizing figures in the history of computer hardware.

Sculley has been working in the technology industry for decades, but conversations about him often go back to his time working at Apple and the reported tension between him and Apple co-founder Steve Jobs which led to Jobs’ firing from the company in 1985.

A technologist from a young age, he operated a ham radio at age 13 and built televisions in his spare time. After getting his MBA from Wharton, he moved towards the marketing side of things, joining PepsiCo in 1967. He is credited with growing many aspects of PepsiCo’s business before he was recruited to Apple by Steve Jobs.

“He was, at that time, developing a new product that was still under development called Macintosh, but Apple had no sustainable business to generate cash other than the Apple II, which was aging at that point,” Sculley said. “My first priority, after joining Apple, was to turn the Apple II sales around and to make it highly profitable.”

He grew the company tremendously under his tenure, making the Apple II profitable enough to help fund the development of the Macintosh and growing the company’s cash reserves as well. Sculley was, himself, ousted by the board in 1993.

Since leaving Apple 21 years ago, he has become a prolific entrepreneur and investor, funding and backing several high tech startups across many different verticals. Sculley currently has about 15 companies in his portfolio such as Misfit, Zeta Interactive, and Metro PCS.

His long career in technology inspired his most recent book Moonshot!, published October 13, 2014, in which he seeks to demystify the process of building transformative companies that focus on consumers.

“I wrote Moonshot to describe to entrepreneurs why the accelerated growth of new technologies like cloud, mobility, unstructured data analytics, Internet of Things — that these technologies were actually creating an incredible power shift from incumbents controlling industries with their traditional established positions to, now, customers in control,” Sculley said.

For new companies, this is the chance to reinvent entire industries. With his book, Sculley is hoping to provide guidance to both the entrepreneurs who will be building new, disruptive companies, and to higher skilled middle-management workers who will be affected by the new technology landscape.

For entrepreneurs, Sculley encourages them to focus on the people first, not the problem.

“The number one advice is: It’s always about the people,” Sculley said. “The talent that you can bring together to create a company is far more important than any idea that anyone has at that time.”

According to Sculley, talented people will always find good ideas to help solve bigger problems. In the book, he addresses these people as “adaptive innovators.” One of the main examples he provides is Kodak missing the mark on digital photography because it didn’t have enough adaptive innovators, it had too much focus on one domain and wasn’t able to pivot when the industry demanded it.

Apple, on the other hand, had quite a bit of experience across different domains. That is what Sculley credits as part of the reason why the iPhone was so successful in changing the way consumers looked at digital photography.

Regarding more traditional corporate IT, he believes that some of the higher skilled middle-management jobs, especially in the US, are going to change. Corporate IT managers will need to adapt and gain new skills to stay relevant and compete in the job market.

The first change in philosophy that Sculley mentioned was the idea that domain experience is becoming much more important than prior technology experience, because the technologies we use are changing so quickly. So, he believes IT workers will need expertise in a particular domain, not just with a specific technology.

On the business side of things, the customer plan is more important than the business plan, Sculley said. This is because the business plan looks back and focuses on incremental improvements, while the customer plan focuses on future achievements and works backwards from there.

Working with startups and large corporations has given Sculley a broad perspective on IT infrastructure. Technology is not the differentiator that it once was. The true differentiator now, he said, is the ability to put the pieces of technology together and build complete solutions.

Looking forward, the Internet of Things (IoT) is Sculley’s technology to watch. He said that the miniaturized sensors popular in IoT products seem to be almost paralleling the early days of microprocessors in terms of performance growth, and he is confident that IoT will reinvent the work processes in every industry.

In his own words…

What do you think about the current direction of Apple?

“I think Tim Cook has done a brilliant job as CEO of Apple. I think he’s taken the hand-off from the vision and the innovations that Steve Jobs created, and he’s developed them into even bigger, more powerful, more successful lines of business. The iPhone 6, I think, is a perfect example of an industry that is rapidly commoditizing and, yet, Apple continues to increase its market share, continues to differentiate, and it has never compromised on the quality of experience for its customers.”

What do you do to unplug?

“My wife Diane is my partner, she is a mathematician and a computer scientist. We travel all over the world together. We don’t have a line between work and fun. So, when we’re over visiting our companies in different parts of the world, we also manage to carve out some time to travel around and see things and visit friends. That’s a really nice benefit of what I do.”

If you weren’t working in tech, what other profession would you love to try?

“I think if I were a young person today I would be studying biology, because of the incredible advancements in biology. I would also be studying higher mathematics. When I was a graduate student in mathematics, we could only dream of what might be possible with things like Monte Carlo game theory, or Bayesian statistical modeling, or Markov chain analysis and things of that sort. Now, those are commonplace with anybody who is involved in marketing automation.”