According to the Harvard Business Review, the role of data scientist was described in 2012 as, "The sexiest job of the 21st Century". IBM ($NYSE:IBM) recently published a study that found that the world needs another 28% data scientists worldwide by 2020 to meet increased demand.

IBM's figure appears to be conservative. According to our data, since 2016, the number of jobs titled "Data Scientist" or containing the term "data science" in their titles has increased multifold. This may be affected by new companies added to our database over time in conjunction with companies changing what they call "data scientists" (many called them "analysts" since 2016).

But make no mistake: companies like Apple ($NASDAQ:AAPL), Amazon ($NASDAQ:AMZN), and Walmart ($NYSE:WMT) need data scientists.

We looked at job listings for more than 5,000 companies since 2016 to gain an understanding of how demand for data science professionals has grown. Demand for data scientists has been on a steady upslope, with more than 3,200 openings as of this month.

As far as who is hiring data scientists, the top-20 companies read a lot like the world's most-successful businesses. It includes such players as Amazon, Booz Allen Hamilton, Walmart, and Apple. The aforementioned IBM study found that 59% of all data science jobs are in Finance and Insurance, Professional Services, and IT, but as you can see by the top-20 list below, demand is diversifying. In short, everyone needs data scientists.

The job is relevant for virtually all sectors of business that deal in data and, let's be frank, that means any successful 21st-Century business that is doing anything with big data. Data scientists discover trends that can alter the future trajectory of a company; they help decision makers gather and gain insights based on the past.

In short, they're the future of business decision-making, and they're desperately in demand.