Here is a look at the biggest trends in the labor market and how these rapid changes are fueling the need for some of these new skills.

This rapid change highlights the importance of reskilling, said Upwork CEO Stephane Kasriel. He added that since many "businesses might not be able to train up their workforce quickly enough," they are likely to depend on freelancers, who "are more likely than traditional employees to participate in skills-related education."

Freelancing platform Upwork today released its newest quarterly index of the 20 hottest skills in the U.S. job market, of which 17 are tech-related. The bigger surprise: 75 percent of the skills are brand new this quarter, proving real-time validation of current trends in the labor market and tech industry.

In this tight labor market, finding people with the right skills to get the job done can sometimes be more difficult than the skill itself. According to the Bureau of Labor Statistics , the U.S. currently has more than 7 million unfilled positions. So while it's a great time to be looking for a job, it's imperative to have the 21st-century skills employers are looking for.

Investments in big data solutions are increasing. Hadoop, an open-source software used to store, process and analyze big data applications, was the fastest-growing skill out of more than 5,000 skills freelancers provided in the fourth quarter on Upwork.com. Businesses are continuing to invest in solutions that allow them to capitalize on the value of their data, specifically leveraging freelance Hadoop experts. According to market research firm Transparency, the global Hadoop market is expected to grow an average of 29 percent year-over-year for the next five years, reaching $38 billion by 2023.

New, nontraditional education options are proliferating. Among freelancers with a four-year college degree, 93 percent say skills training was useful versus only 79 percent that say their college education was useful to the work they do now. As companies realize how critical reskilling is for their workforces, they're turning to workers who are adept in employee training and Learning Management Solution (LMS) consulting to help create programs that encourage cultures of continuous learning. Growth in this area suggests an emerging trend where more people are getting training on the job.

Businesses are doubling down on mobile efforts. Consumers now spend more than five hours a day on their smartphones, and apps account for more than 90 percent of internet time on those devices. Businesses are doubling down on their mobile efforts in order to meet consumers where they are, resulting in a demand for app store optimization and app usability analysis.

Companies are upping customer experience. As more companies undergo digital transformation, they're realizing that design can not only create value and better business outcomes but also help them survive. Organizations who experience the highest return on investment instill a data-driven design approach and successfully integrate design into their business strategy. This is underscored by high growth in demand for Invision, a digital product design platform, and Intercom, a customer-messaging platform that makes apps for sales, marketing and support. Businesses use the tool to more effectively acquire, engage and retain customers.

Rise in cybercrime is spurring growth in security skills. Cybercrime is predicted to cost the world $6 trillion annually by 2021, yet the number of cybersecurity job openings is expected to reach 3.5 million globally by the same year. To access seasoned professionals who have a comprehensive understanding of the IT landscape and can help mitigate risk, businesses are hiring certified information systems security professionals to design, implement and manage cybersecurity programs. Another precaution businesses are taking is beefing up security through OAuth, which enables token-based authentication and authorization online and gives employees a safer and more secure way to access data.