Nir Zuk waited a year for an answer that never came. Inside Juniper Networks he had proposed building a better firewall and asked for three things: ownership of the project, a $10 million budget and 25 handpicked engineers. Nothing. So he gave two weeks' notice.
He was not new to being ignored. Zuk grew up in Rehovot, Israel, where his parents bought him a Dragon 64 computer. He insisted on the 30-megabyte hard drive instead of the 20. He taught himself to program, wrote commercial software as a teenager, and wrote computer viruses.
Zuk grew up in Rehovot, Israel, where his parents bought him a Dragon 64 computer.
What he rarely leads with is that he has no college degree. He started university mathematics during five years in an army unit that wanted whiz kids who could program, and he never finished. He told an interviewer in 2010 that he was one of the first virus developers in the world.
In 1994 he joined Check Point, helped build stateful inspection, and in January 1997 moved to the United States for it. Then the company decided not to release Floodgate, a product his American team had built. He has said Israeli engineers were angry. He also said he likes to develop new technology, and bureaucracy made that hard. He left in March 1999.
He founded OneSecure that month. After the dot-com crash he turned from services to a product he calls the first intrusion prevention system. NetScreen bought it in mid-2002, then Juniper bought NetScreen and planned to retire its products. That was the setting for his unanswered request.
Palo Alto Networks was incorporated on 1 March 2005 with $9.4 million. Zuk says the hardest part of a struggling company is what happens to all the people you hired, and that a company dies when it slides from a can-do to a cannot-do attitude.
It listed in July 2012, raising $260 million, then bought its way into a platform, including Expanse for $1.25 billion in 2020. In the year to July 2025 it earned $1.13 billion on $9.22 billion of revenue, and its market value was about $258 billion on 6 November 2026. Zuk retired as chief technology officer in August 2025.
The quiet lesson sits in that unanswered request. He did not fight for a yes. He took the silence as the answer and left, and the firewall nobody would build became the whole company.