“I’m mostly talking to executive hires at this point. An obvious red flag is if they haven’t done their homework, which still kind of surprises me,” Wacksman told CNBC’s Make It in a recent interview. 

“I’ll talk to folks who are coming in for senior roles, and they’re asking pretty basic questions that you could answer in 10 minutes on Google or 30 seconds in Gemini.”

While waving off unprepared applicants hoping to rest on their track record, the CEO of the $10.5 billion real estate marketplace says he’s looking for candidates who have “thought deeply about the role they’re coming in for. And have thought deeply about what they would add to the job.” It’s the make-or-break factor between landing a C-suite gig or landing in the rejection pile.

One way job candidates can impress Wacksman is by showcasing their intellectual curiosity through asking, not telling. The CEO said that he judges an applicant’s eagerness to learn by the questions they ask—that way, he can assess whether “their passion and their interest [aligns] with the job.” The more “bespoke” the question is to the specific job they’re applying for, Wacksman explained, the better they show “they understand it well.”

Fortune reached out to Zillow for comment.

Thoughtful questions are a secret weapon in the war for jobs

Walking into an interview armed with quality questions may be job-seekers’ secret weapon in the war for salaried roles. 

Kelli Valade, former CEO of Denny’s Corp. who left the food chain last month, has a few tests up her sleeve when it comes to hiring. She asks applicants what makes them most effective at what they do, and tries to parse out their weaknesses by questioning how they could get better. But one of the major signs of a quality hire comes at the end of the process, when she turns the table on the interviewee, and asks: “What questions do you have for me?”

“Have a thoughtful one or two. You don’t really even have to have more than that,” Valade told Fortune last year. “Any more than that, actually, it’s too much.” This trick allows her to gauge if they did their homework, and are genuinely invested in the work ahead. 

Twilio CEO Khozema Shipchandler employs the exact same hiring tactic as Valade, ending his interviews prompting applicants if they have any questions to ask him in return. The job-seeker’s response determines whether or not they’ll make it to the next round; if professionals want a shot at working at the $16.5 billion cloud company, they’ll have to offer more than vacant stares. 

“I give them an opportunity to ask questions, and if they don’t have any, I think that’s a pretty significant mark against them being curious about what they’re interviewing [for]—the company, the way we might work together, chemistry, culture, all of those things,” Shipchandler told Fortune last year. “That’s a pretty big red flag.”

Even recruiters at some of the world’s biggest companies are adopting that golden rule. Jenn Bouchard, chief people and administrative officer at creative agency Figure8, has come to learn that zero questions signal a candidate’s “disinterest” throughout her 17 years in talent acquisition. Having also served as the former global head of talent at Meta, she leaned on those end-of-interview applicant inquiries to pick the best talent for the $1.62 trillion company.

“If candidates don’t have follow-up questions that they’ve pulled through from the interview or if they just say, ‘I’ve had all of my questions answered,’ that’s a red flag,” Bouchard told Fortune in 2024. “An interview is a two-way experience.”