Inside the Network

Tomer Weingarten: From cyber outsider to building SentinelOne into a $1B ARR category leader

In this episode of Inside the Network, we sit down with Tomer Weingarten, Co-Founder and CEO of SentinelOne, one of the fastest-growing cybersecurity companies. From writing code and designing the company’s first UI himself, to taking SentinelOne public and crossing $1 billion ARR, Tomer’s journey is a rare combination of technical excellence, grit, and long-term conviction. Tomer didn’t grow up surrounded by startup founders or Silicon Valley mentors. He was raised in a small Israeli town with few resources and found computers as a creative escape. He met his SentinelOne co-founder, Almog Cohen, in second grade, began hacking games as a teenager, and exited his first startup at just 24 making millions of dollars. Then, in an unusual move, he spent all the money to reset, stay grounded and hungry to build something big. That big ambition would become SentinelOne. When SentinelOne launched in 2013, most endpoint vendors were still focusing on signature-based antivirus, and the idea of autonomous, behavior-based prevention powered by AI sounded like science fiction. Tomer wanted to reimagine cyber defense from the ground up. The company’s early traction didn’t come easy, and it took several years of heads-down engineering effort to get to the point when the company signed its first customer and investors stopped being skeptical. Tomer believed the problem wasn’t being solved deeply enough, and he stayed patient while the market caught up. Tomer shares how he navigated the “wartime CEO” moments like fighting off rivals with 10 times the budget, managing internal politics, and surviving near-death moments during fundraising. He reflects on how leadership styles evolve under pressure, and how the discipline of writing down decisions helped him become a better CEO. He also breaks down how founders confuse early ARR with true product-market fit, and why most security companies today are in his opinion workflow wrappers, not tech companies. We also explore Tomer’s views on the LLM hype cycle and why he believes most of the AI noise in cybersecurity today is more marketing than the actual deep tech. Tomer believes that true moat lies in foundational models trained on real, curated telemetry, and in solving hard tech problems, not just ChatGPT integration. This episode is a deeply personal look at what it takes to build enduring companies in cybersecurity. This is one of our most honest, unfiltered founder conversations, and if you care about the art of company-building, you won’t want to miss it.

Sumit Dhawan: Leading Proofpoint’s AI evolution and building toward $5B in ARR

In this episode of Inside the Network, we sit down with Sumit Dhawan, CEO of Proofpoint, one of the largest private cybersecurity companies in the world. With over $2 billion in ARR, Proofpoint protects 85 of the Fortune 100 and is on a bold path toward $5 billion in revenue by 2030. Sumit’s journey is a masterclass in modern leadership. Having graduated with degrees in engineering and business from IIT Roorkee, the University of Minnesota, and the University of Florida, Sumit led major business lines at Citrix and VMware, including overseeing VMware’s $70 billion divestiture to Broadcom, before making the leap to cybersecurity. In 2023, he joined Proofpoint as CEO and began executing an ambitious strategy: consolidate the sprawl of human-centric security, go deep instead of broad, and prepare the company for its next chapter of growth. In our conversation, Sumit shares why he believes empathy is the most underrated CEO trait, how acting like a founder, even inside large enterprises, shaped his leadership, and what it means to have “Apple Watch governance” under Thoma Bravo. He explains how Proofpoint has evolved from email security leader to a broader platform for human and data protection, including its acquisitions of Tessian (AI-native email protection), Hornetsecurity (MSP-focused email security), and Normalyze (DSPM). Sumit also pulls back the curtain on the AI threat landscape, including how prompt injection attacks are already targeting copilots and agents, why AI is both supercharging attackers and empowering defenders, and how Proofpoint built intent-based detection models to defend against sophisticated zero-link phishing. Finally, he lays out three categories of viable cybersecurity startups today: gap-fillers, AI defenders, and category disruptors, and why the last two are more likely to be successful. Whether you’re scaling a cyber startup, selling into the enterprise, or navigating PE-backed growth, this episode is full of hard-earned wisdom from a leader who’s operated at every level of the stack.

Jay Chaudhry: Betting on yourself and building a $40B+ Zero Trust giant in Zscaler

In this episode of Inside the Network, we sit down with Jay Chaudhry, founder and CEO of Zscaler, one of the most valuable cybersecurity companies in the world with a market cap of over $40 billion and $3 billion in ARR. Jay’s journey is unlike any other. Raised in a remote Indian village with no electricity, no running water, and a two-and-a-half-mile walk to school, he went on to build five companies and pioneer the modern Zero Trust cloud security model. Zscaler, his most iconic company, was launched in 2007 with $50 million of his own capital and no VC investment - a bold bet in the middle of a market downturn, at a time when few believed enterprise security could move to the cloud. This episode is packed with powerful lessons from a founder who’s played the long game. Jay talks about the mindset he carried from his early years farming with oxen, how working alongside his wife Jyoti gave him unmatched focus and alignment, and why startups should be “a foot wide and 20 feet deep.” He explains how Zscaler rewrote not just the playbook for go-to-market in security, but also the TCP/IP stack, and the early challenges of selling Zero Trust well before the term even existed. He also shares his wisdom on why most founders pivot too late when their sales motion fails. Jay provides his view of the future of cybersecurity and the Internet itself, from why the private corporate network is dying to why firewalls will eventually go the way of mainframes. Throughout it all, Jay shares a rare combination of conviction, humility, and self-discipline. Whether you’re a first-time founder or running a $10 billion company, this is an absolute masterclass in how to build enduring companies and stay grounded in the process.

Michelle Zatlyn: Scaling Cloudflare to a $70B giant and building a better Internet

In this episode of Inside the Network, we sit down with Michelle Zatlyn, Co-founder and President of Cloudflare, one of the most iconic Internet infrastructure companies in the world. From its launch during the depths of the 2009 financial crisis to today’s $70 billion market cap and 5 million+ customers, Cloudflare has become a cornerstone of global Internet security and performance. Michelle’s journey is remarkable. Raised in a small farming town in Saskatchewan, Canada, she left behind plans to become a doctor and instead teamed up with Matthew Prince and Lee Holloway to tackle an audacious question: “How can we build a better Internet?” Fifteen years later, Cloudflare is the third most valuable cybersecurity company in the world, protecting millions of businesses and powering the modern web. In our conversation, Michelle shares what it really took to build Cloudflare, why grit mattered more than expertise in the early days, how deep trust among co-founders carried them through the hardest moments, and why “just ship it” became a guiding principle that fueled rapid growth. She also reflects on how Cloudflare has avoided the innovator’s dilemma, continuing to reinvent itself even as a public company, and how AI is reshaping the web, including why she believes we need a new business model to create the right incentives for content creators in the age of large-scale AI crawlers.

Joe Levy: Scaling Sophos to $1B+ revenue and defending the 350M overlooked businesses

In this episode of Inside the Network, we sit down with Joe Levy, CEO of Sophos, a 40-year-old cybersecurity company that has quietly become one of the most important global players, serving over 600,000 organizations and generating over $1 billion in revenue.  Throughout his career, Joe has operated with a founder's mindset: thinking in bets, building great teams, spotting technical and market inflection points, and executing with long-term discipline. A great example is Sophos’ recent $800+ million acquisition of Dell Secureworks, adding over 1,000 new team members and significantly expanding Sophos’ managed detection and response and extended detection and response (MDR/XDR) capabilities.  Today’s session is an exciting masterclass on how a technically astute CEO navigates demanding customers, engages positively with Private Equity giants like Thoma Bravo, and partners with MSPs globally, while building a culture of "vulnerability-based trust”. One of the most insightful statistics Joe and his team at Sophos have highlighted is that while there are over 350 million businesses worldwide, fewer than 1 in 10,000 have a CISO.  This episode is packed with practical lessons on founder transitions, managing through personal health crises, and building resilient security organizations. For any cybersecurity founder thinking about the long game, Joe’s story is one you’ll want to hear. As mentioned in the episode, Joe shared a curated list of books he’s been collecting over the years for his daughter, a shelf he calls “my daughter’s bookshelf.” These aren’t just bedtime stories; they’re books that have shaped Joe’s thinking about the world, passed along with personal inscriptions to provide context and reflection. Some were even introduced by his wife, Tracie, and read together as a family, like the James Herriot series, which took nearly a year to complete and left a lasting impression. This isn’t meant to be a definitive reading list - many classics, business books, and philosophical staples are intentionally left out. But it offers a deeply personal window into the stories that have mattered most to Joe as a parent, leader, and lifelong learner. He also shared a second resource: a living document of quotes, mental models, and hard-won career lessons, many of which have shaped his leadership journey and are referenced throughout the episode. You can explore both below. * "Joe's daughter’s bookshelf"   [https://docs.google.com/spreadsheets/d/1p7VvQ0IVwub4w2JKsXhcMfwjlY8BQFNA/edit?usp=sharing&ouid=107786767201967748505&rtpof=true&sd=true] * Quotes & career notes [https://docs.google.com/document/d/1Jl3rNh-l6rWAsJBBKvxVp7YajTnr9s5v/edit?usp=sharing&ouid=107786767201967748505&rtpof=true&sd=true]