So far, over 3,000 people have applied to one open data science vacancy at a US health tech company this year. The top candidates are given a lengthy and difficult task assessment, which very few pass, says a recruiter at the company, who asked to remain anonymous because they are not authorized to speak publicly.

The recruiter says they believe some who did pass may have used artificial intelligence to solve the problem. There was odd wording in some, the recruiter explains, others disclosed using AI, and in one case when the person moved on to the next interview, they couldn’t answer questions about the task. “Not only have they wasted their time, but they wasted my time,” says the recruiter. “It’s really frustrating.”

It’s not uncommon for tech roles to now receive hundreds or thousands of applicants. Round after round of layoffs since late 2022 have sent a mass of skilled tech workers job hunting, and the wide adoption of generative AI has also upended the recruitment process, allowing people to bulk apply to roles. All of those eager for work are hitting a wall: overwhelmed recruiters and hiring managers.

WIRED spoke with seven recruiters and hiring managers across tech and other industries, who expressed trepidation about the new tech—for now, much is still unknown about how and why AI makes the choices it does, and it has a history of making biased decisions. They want to understand why the AI is making the decisions it does, and to have more room for nuance before embracing it: Not all qualified applicants are going to fit into a role perfectly, one recruiter tells WIRED.

Recruiters say they are met with droves of résumés sent through tools like LinkedIn’s Easy Apply feature, which allows people to apply for jobs quickly within the site’s platform. Then there are third-party tools to write résumés or cover letters, and there’s generative AI built into tools on sites of major players like LinkedIn and Indeed—some for job seekers, some for recruiters. These come alongside a growing number of tools to automate the recruiting process, leaving some workers wondering if a person or bot is looking at their résumé.

“To a job seeker and a recruiter, the AI is a little bit of a black box,” says Hilke Schellmann, whose book The Algorithm looks at software that automates résumé screening and human resources. “What exactly are the criteria of why people are suggested to a recruiter? We don’t know.”

Still, generative AI tools for both recruiters and job seekers are becoming more common. LinkedIn launched a new AI chatbot earlier this year, meant to help people navigate job hunting. The hope was that it would help people see better if they align well with a job or better tailor their résumé for it, peeling back the curtain that separates a job seeker and the hiring process.

That came after LinkedIn began rolling out a new set of generative AI tools for recruiters to source candidates in October. With the sourcing tool, recruiters can search a phrase like “I want to hire engineers in Texas,” and profiles of people that may meet those criteria appear, as do other specific skills that may be related to the role. They can also send messages written with generative AI and set automatic follow-up messages. LinkedIn’s data shows that AI-generated messages are accepted about 40 percent more frequently than one-off messages written only by a recruiter.