This founder left his $4 billion company before the IPO because he had an even better idea

These days, he's running his up-and-coming storage startup Cohesity as CEO and sole founder.

Launched in 2013, Cohesity has already raised $70 million in just two rounds, with a $350 million valuation, backed by A-list venture-capital firms Sequoia, Qualcomm Ventures, and others, according to PitchBook.

He made his stripes as an early Google employee, joining the search giant in 2003, the year before its IPO.

"When I started, there were 600 employee at Google. When I left, Google was 3,000 employees," he tells Business Insider. It had become a "big" company, which he didn't prefer, he says.

Still, like so many of those earlier Googlers, the stint left him financially secure for life. His stock options had a $1.20 strike price, he says. Although he wasn't clairvoyant enough to wait until 2017 to sell, when the stock would trade at over $840 a share, he did wait until the stock had become so valuable that he "couldn't sleep at night."

He became an early employee at Aster Data Systems, which was bought by Teradata in 2011 for $263 million.

Then he did the thing that gave him an even bigger fortune and made him a tech industry star: He cofounded Nutanix, the poster child of the unicorn-startup era.

Successful and bored

At Nutanix, Aron helped invent a brand-new storage data center hardware market dubbed "hyperconverged." That's a piece of hardware that stores data but includes some computing power and networking bundled with the computer-management software known as virtualization. It allows companies to affordably string these computer boxes together to grow their infrastructures really large, really fast, and more affordably than traditional storage.

Nutanix and the hyperconverged market became an existential threat to some of the largest IT players around including the now-gone EMC (swallowed by Dell) and VMware.

It threatens Cisco's popular line of "converged" servers and, reading the tea leaves, Hewlett-Packard Enterprise just bought Nutanix's rival SimpliVity for $650 million in cash.

Nutanix raised gobs of money: $317 million by August 2014, at a $2 billion valuation. It was one of the first unicorns — the group of tech startups with private market valuations of $1 billion or more.

It would be 10 months before the IPO finally happened, in September, at which point the stock soared. Nutanix is now worth $4 billion.

But Aron was long gone from day-to-day operations by then, having left in 2013. He's still one of the biggest shareholders in the company, with a 5%-plus stake that's worth about $300 million, according to SEC documents, mostly in a trust for his kids.

To put this in perspective, it's like Packard leaving Hewlett when things were going pretty well and the payoff hadn't yet hit.

Why? Basically, he was bored, and he didn't need the money.

"I’m not going to sit at Nutanix only to make more money. I’m doing this for my passion," he says. "After being there at Nutanix for more than three years, the tech was mature, the go-to-market solid. Me, being a technologist, I wanted to solve the problem for rest of the data center."

On to the next thing

At Nutanix, Aron says customers were asking the company to build a product that did for their backup storage what Nutanix did for their main storage — make it easier and cheaper to grow and manage.

He couldn't get the rest of the leadership team to agree to develop the product the way he wanted to, he says, so he quit to do it himself.

While he has a good relationship with his former cofounder, Dheeraj Pandey (Nutanix CEO), he says, this was not a sanctioned split blessed with seed money.

It was a clean break.

"I have a civil relationship with everyone at Nutanix," he says, but "I did not take money from any of the people associated [with Nutanix]. I did not become adviser. I was scared of IP issues."

He fully admits that his past success has allowed him to take bigger and bigger risks, including leaving his own company right when it was starting to upend its part of the IT world.

His advice for others is the same: "Make yourself financially secure first, don’t shoot for millions. Once you have that success, take a bigger risk and a bigger risk."

Even at this stage of his career, running his own company, it is a learning curve. He's had to learn, for instance, how to properly hire nontechnical people, like sales and ops people, making hard mistakes along the way.

But he's bounced back from those mistakes. The product is earning good reviews, revenue has been doubling each quarter, he says, and the customer base is growing.

Aron was so happy with the growth that he took the whole company, and their families, on a thank-you vacation to Hawaii over the holidays.

And he says he's never been happier.

"One thing I do now is listen to my gut. If my gut tells me that something is wrong, even if everything else looks right, I don’t go forward with it. In the times I didn’t trust my gut, I regretted it. When the thing inside raises that red flag, you’ve got to respect it," he says.