Celebrating 30 years of Insight Partners: Thomas Krane on Tenable and betting early on cyber

As Insight Partners celebrates 30 years of scaling software, we’re spotlighting milestone investments that shaped not only our portfolio — but also the careers of the investors behind them. For Managing Director Thomas Krane, Tenable was a first in many ways: his first cybersecurity investment, his first IPO, his first unicorn, and the first company he backed to cross $100M in revenue.

In this Q&A, Krane reflects on discovering Tenable as a young investor, the product and founder dynamics that stood out, and the conviction it took to champion a non-obvious opportunity into one of Insight’s defining wins.

Tenable is a pioneering leader in the exposure management category, unifying visibility, insight and action to enable customers to identify, prioritize and remediate cyber vulnerabilities. Insight made its initial investment in the firm in December 2015, and the company IPO’d in 2018.

Q: How did your career at Insight begin, and what drew you to the firm?

I joined Insight as a summer intern in 2012 while studying astrophysics at the University of Pennsylvania. Venture wasn’t on my radar initially — I thought working at Google would be the dream job. But after partnering with former Insight investor Harley Miller on a campus startup, I was introduced to the firm. I was intrigued by Insight’s energy and entrepreneurial spirit. They gave you a laptop, an email address, and the green light to go make things happen. That level of autonomy and trust was incredibly empowering.

Even during the internship, I saw how Insight’s early experience in software investing — especially in the shift to SaaS — gave it an edge. There was tribal knowledge in the firm, a deep operational lens, and a bias for action. I took the full-time offer without hesitation. It remains the best career decision I’ve ever made.

Q: How did your early experiences at Insight shape your investing approach, and ultimately, how you thought about Tenable once you sourced it?

Those early years at Insight gave me both a strong foundation and a lot of reps. I joined full-time after interning during college, and was energized by the trust and autonomy granted to me as a junior investor. If you had curiosity and conviction, you could run with your ideas. I dove into more technical areas — cybersecurity, infrastructure — because they were a bit less crowded internally and aligned with my academic background.

I also spent time studying Insight’s earlier successes — companies like SolarWinds and BeyondTrust — which gave me pattern recognition and historical context. I started thinking: What do the next-generation versions of those companies look like in a SaaS world? That’s what led me to Tenable.

Tenable stood out because it reminded me of some of those earlier wins, but with a new model: product-led, community-driven, and quietly dominant. That combination, plus what I’d learned about how to build internal support and drive a process, gave me the confidence to go all-in and advocate for the deal.

Q: How did you first come across Tenable, and what caught your attention?

I first learned about Tenable when we were still investors in BeyondTrust, a portfolio company that had a smaller vulnerability scanning business. Tenable was dominating that space, so much so that BeyondTrust eventually backed out of it. After exiting BeyondTrust, I was eager to connect with Tenable’s CEO. I sent him an email, and he responded that same day.

That conversation led to a meeting just as they were finalizing their CFO search. I built a relationship with Steve Vintz, who became CFO — and now co-CEO — and stayed close. That timing proved crucial. The company was preparing a pre-IPO round, and we were able to position Insight not as just another late-stage check, but as a strategic partner alongside the founder and Accel. That early relationship-building made all the difference.

Q: What stood out about Tenable’s product, market, and team?

Tenable wasn’t a secret. The company was already a market leader, but there was a perception that vulnerability scanning was a “checkbox” commodity. We saw something different. The open-source roots of Nessus gave it a strong, bottom-up community adoption, which was rare in security back then. It was product-led growth before the PLG category emerged.

From a technical standpoint, Tenable was evolving from static scanning to a continuous model, shifting from “scan-and-check-the-box” to ongoing cyber exposure measurement. That subtle change had massive implications. When we spoke with customers and practitioners, their passion for Nessus was clear. That grassroots energy helped build conviction that this wasn’t just a good company; I believed it had breakout potential.

Q: As a junior investor at the time, what gave you the confidence to pursue Tenable?

It was a mix of things: seeing patterns from past deals, trusting the data, and getting the reps. I spent time looking at less successful cyber companies early in my career, and those experiences sharpened my judgment. When I saw Tenable’s numbers — strong growth, efficient acquisition, loyal users — I knew something was working. But I also had to fight through internal skepticism. Some saw it as commoditized, or questioned what our angle would be to win the deal

That’s where relationship-building and timing mattered. I stayed close to Steve and the team, and we worked behind the scenes to position Insight as an operationally engaged partner. We leveraged Insight’s distinctive growth-oriented mindset alongside the resources and expertise of a private equity firm.

Q: What did you learn from Tenable that shaped your approach going forward?

A few things. First, community love matters more than people think, especially in technical markets. If practitioners are pulling your product into companies, that’s powerful. Second, don’t be afraid to back a great business even if the market narrative says “commodity.” If the data and adoption patterns tell a different story, follow that.

Finally, the deal taught me the value of Insight’s scale and flexibility. Tenable wasn’t a vanilla Series C — we helped lead a founder transition, partnered with Accel, and brought in a new CEO who ultimately took the company public. For me, that creative approach is part of what makes Insight different.

Q: What does Tenable represent to you in your Insight career?

At the time, closing that LOI felt like I had made it, even though it was just the beginning. It was the first deal where I truly drove the sourcing, built key relationships, and helped Insight win a competitive process. It gave me confidence and set a bar for how I wanted to show up as an investor.

But more than anything, it was a lesson in how analysts and associates can be difference-makers. Tenable was already an amazing company when I approached them. But with the right focus, timing, and persistence, we earned a seat at the table. We were able to help the company achieve its operational goals, unlocking a successful IPO. That’s the power of Insight’s model.

Q: What do you think defines Insight’s DNA and makes it stand out in the investing world?

Insight’s DNA is rooted in a rare combination of humility, discipline, and curiosity. The firm’s leadership has never taken success for granted — we don’t pretend to know everything. Instead, we rely on our analysts and associates to surface what’s new and important, and we build our conviction from the bottom up.

There’s a true appreciation for data, for diligence, and for being hands-on. We’re not afraid to roll up our sleeves or help transform a business—we’ve done it many times before. And yet, there’s a constant drive to learn, adapt, and evolve. That mindset, coupled with the scale and operational depth we’ve built, continues to set Insight apart.

Note: Insight has invested in Tenable, SolarWinds, and BeyondTrust.