CLEARWATER — It's every entrepreneur's dream: a niche position in an exploding market, a reputation as a trusted problem-solver and a talented, energetic team of employees who enjoy coming to work every day.KnowBe4, a Tampa Bay start-up dedicated to showing its clients how to protect themselves from hackers intent on finagling corporate passwords and private data, has possessed all three qualities since it launched in 2010. A dazzling 360-degree view of downtown Clearwater and the Clearwater Memorial Causeway from the top two floors of Clearwater Tower helps sweeten the pot.Related coverage: A complete breakdown of Tampa Bay's Top Workplaces of 2017The fast-growing firm posted $24 million in sales in 2016, exceeding its goal of $17 million. It received an $8 million cash infusion from a venture capital fund. And in the past 12 months, it grew its employee pool from 70 to 253 to satisfy a client list that more than tripled.All of which contributed to KnowBe4's No. 1 ranking among medium-sized companies in the Tampa Bay Times Top Workplaces survey. The firm debuted on the 100-company workplace list last year with another stellar showing, garnering first place among small companies."We're going 90 miles an hour all day, every day," said founder and CEO Stu Sjouwerman. "We're in a steep uptrend that eventually will taper off, but I don't see that happening anytime soon."A self-described serial entrepreneur with more than 30 years in the IT industry, Sjouwerman, 60, set out seven years ago to create a company to help businesses combat "social engineering" schemes, where hackers attempt to trick users into disclosing passwords or other sensitive information rather than relying on traditional hacking techniques.As part of its training strategy, KnowBe4 uses "penetration tests" against client companies, playing the role of a hacker. The firm then points out weak spots and identifies employees who may be vulnerable to hackers passing themselves off as legitimate business people.KnowBe4's success was reflected this past year in its meteoric rise from No. 139 to No. 38 on Cybersecurity 500, the definitive list of the world's most innovative companies in the cybersecurity industry, and by its appearance on the Florida Fast 100, which ranked it second in the country by percent of growth from 2013 to 2015.By October, KnowBe4 had tackled a new attack vector that combines the triumvirate of fraudulent attempts to gain sensitive information —phishing, vishing and smishing — and boasted more than 6,000 enterprise accounts.After adding another 750 clients in December, the company topped 8,000 accounts and announced a year-over-year sales increase of nearly 300 percent for fourth quarter 2016.Sjouwerman takes the company's success in stride, attributing its phenomenal growth to his knack for identifying a new category in the market that required a new type of product and then becoming the largest provider in that category.Having a home base in Clearwater doesn't hurt, he added."Being in the Tampa Bay area provides a great employee pool," he said. There are tons of talented people in sales, technology and customer service, so good team members are not hard to find."One of Sjouwerman's recent hires is Miesh Blankenship, who, despite being new to the cybersecurity industry, felt confident she could sell KnowBe4's product after an intensive, two-week training period."There was a magical point, and it happened very soon, where it all came together," Blankenship said. "I had confidence in the product and I knew I could sell it."Sjouwerman promoted her to regional account manager within three and a half months.The company's policy of promoting from within and offering cash bonuses for meeting sales quotas are two of the reasons potential employees send their resumes unsolicited, said HR director Michele Weisensee."Word gets out," Weisensee said. "But to work here, you have to be able to handle change, because change happens on an almost daily basis."The potential for more change — and more growth — accelerated recently with the hire of Perry Carpenter, a research analyst Sjouwerman lured away from Gartner, a world leader in information technology research and advising. Carpenter will assume the title "chief evangelist and strategy officer" and will be charged with keeping KnowBe4 on track to reach its 2017 sales goal of $45 million and its five-year goal of $80 million.But no matter how much KnowBe4 grows, Sjouwerman says he will continue to preach its three golden rules, which he believes contribute to a contented workforce, the most reliable indicator of a top workplace: Do it right the first time, do it fast and have fun while you do it.