Jo Weech, a Washington-based recruiter, found a software engineer she planned to hire, one with skills and experiences so rare she dubbed her a “purple unicorn,” recruiting-speak for a perfect find.

This candidate aced multiple interviews for a job supporting a federal contract. She breezed through a technical test. She had already nabbed a top-secret security clearance. Hiring managers wanted to bring her onboard. Weech called the candidate, intending to make an offer.

Suddenly, calls and texts went unreturned. Weech asked a colleague to reach out; he also got nowhere. Weech sent playful notes: “Please let me know that you have not been kidnapped by aliens. I’m worried about you.” She left voicemails. Then she started to get concerned: Was there an emergency in the candidate’s family? An illness? Car accident? Determined to make contact, Weech bought a greeting card and sent it via snail mail. Over three weeks, the engineer ignored a dozen messages.

Weech had been ghosted at work.

In fields ranging from food service to finance, recruiters and hiring managers say a tightening job market and a sustained labor shortage have contributed to a surge in professionals abruptly cutting off contact and turning silent — the type of behavior more often associated with online dating than office life. The practice is prolonging hiring, forcing companies to overhaul their processes and tormenting recruiters, who find themselves under constant pressure. “If you don’t love your job [as a recruiter], you’ll beat your head on your desk,” says John Widgren, a recruiter for Central Florida Health, a more than 3,000-employee health system outside Orlando.

Where once it was companies ignoring job applicants or snubbing candidates after interviews, the world has flipped. Candidates agree to job interviews and fail to show up, never saying more. Some accept jobs, only to not appear for the first day of work, no reason given, of course. Instead of formally quitting, enduring a potentially awkward conversation with a manager, some employees leave and never return. Bosses realize they’ve quit only after a series of unsuccessful attempts to reach them. The hiring process begins anew.

Among younger generations, ghosting has “almost become a new vocabulary” in which “no response is a response,” says Amanda Bradford, CEO and founder of The League, a dating app. Now, “that same behavior is happening in the job market,” says Bradford, who’s experienced it with engineering candidates who ghosted her company.

Some of the behavior may stem not from malice, but inexperience. Professionals who entered the workforce a decade ago, during the height of the Great Recession, have never encountered a job market this strong. The unemployment rate is at an 18-year low. More open jobs exist than unemployed workers, the first time that’s happened since the Labor Dept. began keeping such records in 2000. The rate of professionals quitting their jobs hit a record level in March; among those who left their companies, almost two thirds voluntarily quit. Presented with multiple opportunities, professionals face a task some have rarely practiced: saying no to jobs.

“Candidates are winding up with multiple offers, and you can’t accept them all,” says Dawn Fay, district president at Robert Half International in New York. “Individuals just inherently don’t like conflict or disappointing people.”

Thus, ghosts. Interviews with more than a dozen hiring managers and recruiters across the U.S. suggest the practice is on the rise, forcing companies to rethink how they operate.

Some recruiters have started to borrow from the airline industry, copying its approach to selling more tickets than seats. Meredith Jones, an Indianapolis-based director of human resources for a national restaurant operator, now overbooks interviews, knowing up to 50 percent of candidates for entry-level roles likely won’t show up. If a candidate passes a background check, clears a drug screen and cheerfully accepts a job offer, showing enthusiasm every step in the process, she knows trouble could still lie ahead. So on a candidate’s first day, she typically calls hours before start time, offering a friendly reminder: Look forward to seeing you later! Even this is no guarantee.

“I’ve had it where, I talked to them that morning to confirm what time they’re coming in that afternoon, and then they don’t show up,” she says. “They stop returning your phone calls.”

And suddenly the recruiter is now a telemarketer. In Jones’ case, once a recruit ghosts, she and a hiring manager will typically make three to five calls to the incoming employee. The first call assumes good intentions; perhaps someone is hurt or dealing with a personal situation. The last call is more direct: Consider this notice the job offer has been rescinded.

In a previous HR role, Jones would often note in an internal tracking system whether an applicant had failed to show up for an interview or job offer — a blackball that would ensure the candidate did not get hired in the future. But she says she needs no database for ghosts. “I have a list of names in my head that have burned me so bad,” she says.

At Hollywood Casino in Baton Rouge, La., VP of HR Robin Schooling advises her hiring managers to interview continuously since it’s unclear when someone may abruptly drop out of the process. Her team hires about 200 people annually, many for front-line positions such as servers, table hosts, cooks, valet parking attendants and similar roles.

In the past month, the casino’s had four individuals accept a job and then fail to show up for onboarding only days later. When members of Schooling’s team reached out to one candidate, this person “literally hung up the phone.” She said she sees the behavior in people of all ages, and is baffled when a ghost will show up again months later, reapplying. Schooling explains to these people that they disappeared previously and, therefore, will not be reconsidered. Some get angry. “People don’t stop to think about the small world we live in,” she says. “People in HR and recruiting have really long memories.”

The trouble is not limited to minimum-wage work. About a tenth of registered nurses go dark entirely after Central Florida Health's Widgren reaches out to extend an offer at his organization, which operates two hospitals outside Orlando in addition to a rehabilitation facility and a lab network. Talk of ghosting came up “all the time” among his peers in the industry, he said. The common refrain: “I can’t believe it happened to me.”

Tight job markets are not without precedent. Companies echoed similar complaints about finicky employees in 2000, ahead of the dot-com crash.

And candidates — scarred from years of applying for jobs, spending hours preparing for interviews, only to get form rejections back — may not be to blame for going cold, said Peter Cappelli, a management professor and director of Wharton's Center for Human Resources. “I think they have learned it from the employers,” he said. “Employers were notorious for never getting back to people, and only letting them know what was going on if it turned out they wanted them to go to the next step.”

He added: “The employers have been far worse about this than any of the job seekers.”

Still, HR teams are bemoaning the emotional rollercoaster they’ve suddenly found themselves on, dealing with the kind of “what just happened?” situations once reserved to those on the dating circuit.

Earlier this week, Kristen Randolph, an HR manager at Metro Plastics Technologies, a 120-employee manufacturer in Noblesville, Ind., sent an email to her boss in desperation. “‘I feel like I’m failing,’” she wrote. “It’s my job to keep this place staffed. It’s my job to keep it running, and I can’t even hire people because nobody wants to work.”

Her manager quickly reassured her, understanding the difficulties of a prolonged labor shortage. While her company has adjusted its schedule — work 30 hours, get paid for 40 — and thrown in perks like free cell phones for employees, filling vacant positions is a daily challenge. Randolph’s calls and emails go unreturned and it’s common for people to not show up for interviews or to stop appearing at work entirely, a situation that happened three times this week. “Usually, you get their names memorized when they stand you up or ghost you,” she says. “It’s definitely a red X on them.”

Weech, the Washington-based recruiter who is CEO of Exemplary Consultants, participates in a 125-person networking group for recruiters that has morphed into what she describes as a quasi support community. Her role: “sort of like a therapist” to those struggling to hire.

She is open about her tips and experiences. The engineer who ghosted ultimately did get back to her — six weeks after her call — to say she had accepted another job at her current employer. She never apologized for her unresponsiveness.

Recruiters say there’s an easy way to ease such frustrations: communicate. Don’t accept jobs if you’re not serious about taking them. If you do need to drop out of the process, say so.

Marie Artim, vice president of talent acquisition for car rental chain Enterprise Holdings, which hires about 8,500 workers annually for entry level management positions, says it’s important for both recruiters and candidates to be courteous with each other. That’s partly because careers take many turns; hiring managers and candidates will both likely end up at different companies in the future, so closing the door respectfully is essential.

While Enterprise experiences some ghosting, Artim’s teams have also seen candidates turn down jobs via text message. “They send a text and they’re like: ‘I took a job and I’m no longer interested in that, thanks.’”

Could the level of professionalism be higher? Sure. Would most candidates want a recruiter to text them to say they didn’t get the job? Probably not. But, still.

“At this point,” Artim says, “as long as we hear back from someone, that’s a step in the right direction.”

This article is part of Work in Progress, a new series exploring what it means to earn a living today. Subscribe to our podcast on iTunes or Google Play and see more stories at #WorkInProgress.