Professional staffing firm CyberCoders, part of On Assignment Inc. (NYSE: ASGN), listed its most in-demand skills for professionals the IT, construction and accounting verticals in the fourth quarter.

For job-seekers in IT, React, a JavaScript library used for building user interfaces within large platforms such as Facebook and Instagram, topped the list as the most in-demand skill.

“With Airbnb, Instagram and Uber as just a few technology firms utilizing this powerful framework, it’s no surprise that React tops the list as the most in-demand skill in IT,” said CyberCoders President Shane Lamb.

Mortgage skills topped the list in the accounting vertical, and construction estimating is the most in-demand skill in the construction industry.

Here are the lists of the fourth quarter’s top in-demand skills and areas of expertise by industry:

IT:

1. React
2. Docker
3. Node.JS
4. Angular
5. Machine learning

Accounting:

1. Mortgage
2. Financial reporting
3. Tax planning
4. Public accounting
5. Corporate tax

Construction:

1. Construction estimating
2. Project management
3. Commercial construction
4. Multifamily construction
5. Retail construction

“Many people think January is the right time to begin a job search, but our data represents the high demand for skilled talent in every industry in Q4,” Lamb said.

CyberCoders is based in Irvine, Calif. It derived the list by analyzing data points from more than 11,000 job postings.