If it seems like it's taken a long time for that recruiter to call you back, or for that first interview — and second, and third — to turn into a job offer, you have company. According to a new report by Glassdoor, the interview process looks to be taking longer than ever.

The report, released on Thursday, analyzed more than 340,000 "interview reviews" that job candidates and employees have submitted on Glassdoor's careers site over the past six years. It examined differences in how long it takes to interview in various job categories, sectors and cities. Washington, D.C., is the slowest city in the nation by far, job seekers say.

Its findings also suggest a sharp rise in the overall length of the average interview process in the United States — 23 days in 2014, up from about 13 days in 2010. (After controlling for some factors, that rise looked somewhat smaller but still significant.)

"My belief as an economist is that it has to do with a shift away from more routine jobs, to those that require more judgment," said Andrew Chamberlain, Glassdoor's chief economist. "Those jobs are harder to screen for, and more costly if you make a mistake hiring for them."

Indeed, Chamberlain's study showed that more and more job candidates are reporting the use of various screens or tests in the interview process. The percentage who say they faced a background check has grown from 25 percent in 2010 to 42 percent in 2014. Skills tests, drug tests and personality tests have also grown in usage somewhat, according to job seekers.

All that caution, however, could have a downside. "If you make the choice to do a background check on every employee, it's going to take longer, and you risk losing them to someone else," Chamberlain said. "All these things stack up and create more delays. Maybe you don't need all those things to get the right match."

Glassdoor's study is hardly the only one to look at how long it's taking companies to hire. Each month, the DHI-DFH Mean Vacancy Duration Measure captures the average time it takes to fill a job opening, using Labor Department data. The most recent report showed it has grown to an all-time high of 27.3 working days (defined as Mondays through Saturdays). As The Washington Post's Catherine Rampell noted Tuesday, this "important and underappreciated monthly data release" shows that "many companies are acting like big teases. They say they want to hire, then drag their feet."

Like many surveys, Glassdoor's report relies on something much less exact than data from the Bureau of Labor Statistics — the recollections of job seekers. As a result, it's possible some people underestimated the time it took for them to go from first phone call to job offer, while others could have exaggerated it. In addition, some people submit interview reviews even when they don't end up getting a job, so a portion of the sample doesn't reflect actual hiring time.

Still, the study offers a snapshot of how employees themselves view the process. And its findings, in line with other surveys, show how much longer such applicants wait when interviewing for positions with bigger companies or for government jobs.

Perhaps one of the most interesting aspects of the study is that it explored how the interview-process length varies for different positions. It takes just seven days to get through interviews as a waiter or a line cook, but 55 to become a senior vice president and nearly 59 to be an assistant professor, candidates said.

But those interview times were still a bit shorter than the average reported for government jobs, which clocked in at 60 days in the United States — longer, it should be noted, than in Australia, Canada or the United Kingdom.

That's likely a big part of why the Washington area had the longest average interview process, at about 34 days, which is 36 percent longer than the next highest city, Portland.