Demand for workers with the right IT skills appears insatiable. The war for talent has made it especially hard to find and place these workers. What are some of the most in-demand IT skills? What are the hardest-to-find?

Here’s what we found when we took a look at the landscape and asked experts involved in recruiting tech talent. We also reviewed Staffing Industry Analysts’ research about in-demand skills and how the need is evolving.

To begin with, experts confirm the need for IT professionals will keep growing.

The TechServe Alliance, the trade association of the IT and engineering staffing and solutions industry, estimated IT employment in the US rose 4.1% over the 12 months ended in September to 4.99 million — just under the 5 million mark.

While IT used to be just one part of a business, says TechServe Alliance CEO Mark Roberts, it is now an integral part of all businesses and demand for tech talent isn’t letting up. In addition, there are new technologies being developed that will require personnel. The IT space will just continue to add jobs.

“Now IT is so integrated into every aspect of running a business, it’s very much at the core of being competitive,” Roberts says. “There is unlikely to be any sign of that demand abating; it just permeates every aspect of what a business does these days.”

However, supply of these workers looks tight. There are specific IT skills that recruiters are having the greatest challenge finding.

The unemployment rate for US workers in “computer and mathematical” occupations recently went from low to lower, according to research from Staffing Industry Analysts. The occupation’s median quarterly unemployment rate in the third quarter of 2014 through the second quarter of 2015 fell to 2.4% from the same period a year earlier when the rate was 3.3%.

IT staffing ranks as the second largest segment of staffing in terms of revenue — just after industrial staffing — and revenue is set to grow 6% this year to an estimated $27.2 billion, according to research by Staffing Industry Analysts. Other staffing segments are growing faster — healthcare staffing revenue is set to jump 17% this year — but the outlook for IT staffing remains solid. Possible explanations for the more modest growth in IT staffing revenue include widespread use of managed service providers and vendor management systems to keep prices down as well as competition from offshore IT solutions providers, according to the report.

But there’s no arguing about demand. “I would say that it is growing and it will continue to grow even through a downturn or upswing,” says Taso Du Val, co-founder and CEO online staffing platform Toptal. “The lack of talent is so great and the need so high … the demand is essentially going to be infinite.”

Toptal was founded in 2010; Du Val founded the firm because he felt other online platforms didn’t have quality workers and that top-notch developers were reluctant to put their shingle up on sites with lower quality workers. Toptal aims to include only the top 3% of developers. The company operates on a 100% remote basis; everyone at the firm works out of a home office.

The Skills

In terms of skills, Du Val says he sees demand trending upward for AngularJS, Java Script and mobile.

And TechServe Alliance’s Roberts points to developers being in demand, with .Net and Java workers in particular need. “There are other skill sets that are smaller, but those are by far the lion’s share of the most difficult to find skill sets and where clients need them in great numbers,” he says.

Java is a programming language while .Net is a Microsoft operating system platform. And they were cited by other staffing experts as well.

“The ones that we’ve seen most have been .Net, SQL, Java, and really those have been the same things that have been for years,” says Jeff Rosen, regional VP of Beacon Hill Technologies, adding that skills in mobile are also in demand.

Based in Boston, Beacon Hill ranks on Staffing Industry Analysts’ 2015 list of fastest-growing US staffing firms.

Rosen says technology’s nature of constant change will continue to spur demand for IT professionals to help companies implement the latest technology. There’s also a shortage of new grads going into the field, he says. “I think the college advisers and professors are not telling people the right things, there are so many jobs out there.”

Demand likely won’t slow down either, he says. “I’ve been doing this for 20 years, I keep hearing it’s going to slow down or it’s going to change.” So far it hasn’t.

Jeff Harris, CEO of ettain group, also says software development skills — which includes Java and .Net — are among the most in-demand. In addition, the healthcare industry is generating demand for electronic healthcare records software such as Cerner and Epic. Data analytics follows software development in terms of demand and they are seeing a strong growing demand in digital experience for frontend Web developers and user experience/ user interface skills among other requirements.

Charlotte, N.C.-based ettain group provides IT, creative and healthcare IT talent solutions and also appears on Staffing Industry Analysts’ 2015 list of fastest-growing US staffing firms.

The demand hasn’t been unnoticed by workers.

“Anecdotally, we are hearing from our candidate base that they have more and more opportunity,” Harris says. “Consequently, it’s become more important to work with staffing buyers to manage an efficient recruitment process with a sense of urgency, and market those opportunities effectively so they don’t lose potential IT talent to others competing for that talent,” he says. “Staffing buyers have always needed to offer a reasonable salary, but IT candidates also look for opportunities to learn as well as do interesting work.”

Difficult to Find

There’s not a direct correlation between in-demand skills and skills that are difficult to find, Harris says. “Any good IT candidate is difficult to find, but I would say that the top five skill sets that we recruit for are probably not the most difficult to find, because there are more of them for every opening.” In the second half of the top 10, on the other hand, the skills are more difficult to find but there may not be as much demand for them. For example, information security and software architects are not in ettain’s top five in terms of demand but are still in the top 10 and tend to be difficult to find because of greater scarcity of talent in those fields.

IT positions consistently rank among the hardest-to-recruit skills, according to the surveys of contingent workforce buyers by Staffing Industry Analysts.

In the 2015 survey, the most commonly mentioned difficult-to-recruit skills among IT staffing buyers were:

  1. Data/data science. These skills weren’t often mentioned in last year’s buyer survey. Commonly cited positions included data scientists, data specialists and data architects.
  2. Information security. These roles include IT security specialists and SailPoint roles.
  3. Java. It ranked among the top three skills for the third year in a row in 2015, and Java was the second most-commonly cited last year.
  4. Project management. It also appeared on the list (although not in the top three) for the third year in a row.

In addition to those skills, other commonly reported difficult-to-recruit IT skills included (in order of mentions) business intelligence, legacy systems, SAP and TIBCO.

In a 2014 report based on an earlier staffing buyer survey, the most difficult skill sets included business/enterprise software, Java, project management/ leadership, business analysts, mobile developers and .Net developers.

However, the issue of supply is the key concern, some experts say. The US doesn’t have enough tech grads and firms can’t bring in enough workers from overseas.

“I think the biggest challenge is the supply one,” says the TechServe Alliance’s Roberts. “We’re just not training and educating enough folks domestically. … You have strong high demand and yet the supply is inadequate. It’s either domestic supply or bringing folks in, and both of those are inadequate to meet demand.”

Without either, it pushes firms to go overseas to get work done, he says. But that is another story.