Denis Yarats spent his Ph.D. years deep in machine learning research at NYU’s Courant Institute of Mathematical Sciences, writing papers and solving computational problems. He never planned on starting a company, let alone stepping into Google’s backyard.
Today, as co-founder and chief technology officer of $20 billion startup Perplexity AI, he is challenging the dominant search engine with a new AI-powered alternative. Yarats credits his four years at NYU for the mindset that made it possible.
In an interview with WSN, Yarats spoke about how his Courant education led to Perplexity, why he competes with trillion-dollar companies and what it takes to keep a growing startup moving at breakneck speed.
This interview has been edited for length and clarity.
WSN: How did your time at NYU shape your approach to building Perplexity?
Yarats: Ph.D. programs teach you how to focus deeply for a long time on one problem, rather than doing a lot of different things but only broadly. Usually, important things require going very deep and doing something complicated. It’s never going to be perfect, but perfection should be the ultimate goal so you can get better and better every day — that experience allowed me to apply those learnings and create a company.
At Courant, Yarats researched reinforcement learning — which he said is a foundational technology behind the artificial intelligence revolution — and was focused on academic work, not commercial applications. But after realizing the technology’s practical potential, he partnered with Aravind Srinivas, a researcher at the University of California, Berkeley who was exploring similar problems.
Yarats left his Ph.D. program early to pursue the San Francisco-based startup — a leap of faith, even with his work experience at Microsoft, Quora and Meta. One of the NYU professors that oversaw his research, Turing Award winner and pioneering AI scientist Yann LeCun, validated his decision by becoming an early seed investor and promoting the product to others in the industry.
Perplexity now has over 300 employees and tens of millions of monthly users, but it’s still competing against tech giants with far more resources and market share. For Yarats, the lopsided fight isn’t intimidating — it’s motivating.
WSN: How do you go about taking on trillion-dollar companies?
Yarats: You always need to have a target, and obviously, Google is the ultimate target. Even if you look at the history of how Google was made, at some point they were also an underdog, and that’s very inspiring, to be honest. We don’t have the same constraints that they have, so we can try different things much faster and see what is working. Some people wouldn’t even start because they are scared that going against Google is impossible, but I think it’s possible.
With backing from Jeff Bezos and Nvidia, Perplexity recently expanded with its agentic AI browser Comet. The company is also known for making bold moves: Perplexity submitted a proposal to merge with TikTok U.S. ahead of its potential ban in January, and later bid $34.5 billion for Chrome amid Google’s yearslong antitrust litigation.
The company’s rapid growth has brought controversy, however. Perplexity has faced accusations of copyright infringement from The New York Times, the BBC and other major news outlets. Separate investigations by Wired and Cloudflare found that the company uses web crawlers that bypass website protections. Perplexity has since launched a revenue-sharing program for its publishing partners, such as Time magazine and the Los Angeles Times, to mitigate plagiarism concerns.
For Yarats, sustaining the startup’s momentum requires treating work as a way of life. He said starting a company is “the best experience,” though he hopes Perplexity will be the last one he works at.
WSN: What does it take to build and maintain a company like Perplexity?
Yarats: I wouldn’t say it’s like a job, it’s more like a lifestyle. If you want to start a company, you basically should assume that it’s going to take all the time that you have. Sometimes on the weekend, I am like, ‘OK, so what can I do?’ and then I realize there is nothing more exciting than going back to work. If you can build an environment where your work is the most interesting thing that you can be doing, it makes it so much easier.
As Perplexity scales, its New York City footprint is growing with a new office in Union Square, bringing Yarats back to where he first began building the product. He said he sees the city as an ideal place to find strong engineers and build infrastructure.
Yarats said the company is “user-obsessed” and prioritizes fixing bugs over metrics like valuation or headcount. It’s this singular focus on the product that he believes will determine whether Perplexity becomes a household name.
WSN: Three years in, does running Perplexity feel different?
Yarats: Even though we have over 300 people right now, it still feels like a small startup because of our culture and how we like to run things. People solve hard problems while being very humble. We like trying to avoid the mindset of ‘We made it’ at all costs, because I don’t think it’s a helpful attitude. Every day can be the last day.
Contact Krish Dev at [email protected].