GoodData founder and CEO Roman Stanek has had a fascinating career. He's a native of Czechoslovakia, and got into software and started his first business when the Soviet Union was falling and eastern Europe opened up.

His first company, NetBeans, sold to Sun Microsystems. His second, Systinet, was acquired by Mercury Interactive, then Hewlett Packard.

Now he's leading his third startup, a cloud analytics and business intelligence company which he started in 2007, when most were still wildly skeptical about the technology. We spoke to Stanek about the key lessons he's learned in nearly 20 years as an entrepreneur.

There's no one else to blame when things go wrong.

Stanek's most fundamental advice for prospective entrepreneurs? You cannot pass the buck.

"I usually tell people that being a founder of a startup, it's one big giant mood swing," Stanek says. "Every CEO's job is a very lonely job."

Despite the fact that you have a network of people that support you, at the end of the day, all of the responsibility lies with the founder and CEO. There's no one to hide behind.

And that means particularly large mood swings, because for small companies, "every piece of news is existential," Stanek says. When your competitor comes out with a similar product, you win or lose a big deal, it's something the whole company has to react to, the CEO in particular. There are few easy days.

It's something that Stanek seems to relish. This is his third time around, but prospective founders have to be prepared.

An entrepreneur's greatest tool is confidence. Sometimes it's all you have.

Everything about a new business is asking people to take a gamble. And it's all up to a founder to convince everybody.

"What I've learned over the past 20 years is that at the end of the day, the name of the game is confidence," Stanek says. "It's confidence that you give to your people, it's the confidence you give to your board and investors that if they invest in you they will actually make money, and it's also confidence to customers, because early customers are making a big bet on a small startup."

And it isn't always about having all of the answers. You have to have the more intangible ability to build confidence even when things are unknown.

"I have to actually instill that confidence and give people reason to show up the next day and be excited," Stanek says, "all in a situation of extreme uncertainty about what are we doing, is anybody going to buy this? In many cases the only tool you have is confidence. You cannot always tell people 'this is why,' you to have tell people that you have confidence and convince them to believe in you."

As a leader, culture is your job.

When you first start out, it's all about aggression and selling and promotion. When you get bigger, you have to think about culture, being inclusive, and communicating well.

You have to think about what kind of company you want to be. "Culture is my main focus," Stanek says. And his biggest goal is to make sure he leads a learning organization, one that constantly changes and improves. So key objectives are set not just to make sure people hit targets, but to create data, to give people the ability and knowledge to improve.

The need for that culture has taken Stanek time to learn.

"My assumption over ten years ago was that a startup is just a smaller division of IBM. That they had the same functions only on a smaller scale. And it took me ten years to realize that a startup is a fundamentally different organization," Stanek says. "We function as a learning organization. Every day when I go home I have to think about 'what did I learn today?' 'What can I do to actually make the company better tomorrow?'"

Be persistent, especially in the face of skepticism.

When Stanek attempted to raise money for GoodData, his timing wasn't particularly good. He had a venture capitalist meeting on the September day in 2008 when Lehman Brothers collapsed. And at the time, "every single VC I went to told me that nobody will ever give you their data, they will never go into the cloud," he said.

The fact that Stanek could go out and buy the domain name "gooddata.com" tells you something.

We asked him if he ever doubted the transition to the cloud. "Never," Stanek replied.

And now that persistence has paid off. The increase in cloud technology and the value of data has surpassed what even Stanek might have predicted 6 years ago.

"We faced many many challenges when we started," Stanek said, "and now, that's why it feels so good, we feel like we were in the right place in the right time."

If something's new enough for people to doubt it, it's often a good sign rather than a warning signal. You just have to have enough confidence to power through the difficult first years.