Description:
Lee Rossey is the CTO and co-founder of SimSpace, and he’s spent the last 25 years building in the deep end of cybersecurity, including 15 years at MIT Lincoln Laboratory. His worldview is refreshingly practical: if you can’t measure it, you don’t really understand it… and if you can’t test it under pressure, you don’t actually trust it.
In this episode, we dig into what “proving grounds” means in the AI era. Red teams and penetration tests are valuable, but production systems have guardrails for a reason. You can’t take down a hospital, bank, or power company just to prove a point. SimSpace helps organizations create realistic, representative replicas of their environments so they can push tools and teams to failure safely, run repeatable attack scenarios, and build true muscle memory.
AI is the accelerant on both sides. Defenders use it to cut through noise and respond faster. Attackers use it to craft more convincing lures, move through kill chains quicker, and exploit complexity. Lee’s core message lands clean: the future belongs to the organizations that don’t just buy AI security, but prove it… in reality… before betting the business on it.
Key Takeaways:
- AI security needs proving grounds, because “trust” has to be earned through testing, not marketing.
- Production environments can’t be fully stress-tested, so realistic replicas are how you train and validate safely.
- Automation makes testing practical. If building the environment takes months, it won’t happen often enough to matter.
- The kill chain is compressing. AI reduces the time from recon to exploit, so defenders must shorten detection-to-response.
- Agentic tools introduce new attack surfaces like prompt injection and manipulation of decision-making.
- Humans aren’t disappearing, but their role shifts. The new norm is operators working side by side with AI.
Lee Rossey
Lee is a former Group Leader at MIT Lincoln Laboratory, where he established the Cyber System Assessments Group, which became a nationally recognized centre of excellence. He led the group in cyber range development, cyber test and evaluation, cyber red teaming, and cyber exploitation as well as the deployment of the LARIAT traffic generation tool. As Group Leader, Lee worked with DARPA, testing, and evaluating over 30 classified and unclassified programs. He also worked with the Air Force.
Lee led several national studies for the Department of Defense to identify and assess existing capabilities, develop an approach and roadmap for their consolidation and advancement and provide the roadmap for the future, which laid the foundation for the National Cyber Range Complex, the Persistent Cyber Training Environment, and other specialized testing and training facilities.
Since 2015, Lee has served as the Chief Technology Officer and Co-Founder at SimSpace. The SimSpace platform is being used as the solution for USCYBERCOM’s Persistent Cyber Training Environment and for other militaries around the world as well as many commercial customers.
THE MEAT OF IT!
- Why proving grounds matter now
- Non-linear paths, career pivots, and learning what actually fits
- Letting go of inherited narratives about success and intelligence
- Lee’s path: MIT Lincoln Laboratory to SimSpace
- National security mindset: evaluate, test, measure
- Spinning out when the tech and teams matured
- What a cyber range actually is
- A high-fidelity replica you can break safely
- Training operators and validating tools in the same environment
- From red teams to automated scenarios
- Why production pen tests have guardrails
- Running repeatable “APT-style” attack chains at scale
- The first principles behind the platform
- Labeled data, realism, and measurement over PowerPoints
- Reducing signal-to-noise so humans can respond faster
- AI introduces new risks to model
- Agentic tools, prompt injection, model drift, and “why did it decide that?”
- Humans + AI side by side as the new operating normal
- Who SimSpace serves and what’s next
- Reclaiming creative identities over long time horizons
- Building a life where meaningful work and sustainability coexist
Check out these related Episodes:
- Episode 262: Robert Siciliano – Building a Human Firewall in a World That Trusts Too Easily
- Episode 252: Oksana Kovalchuk – Rebuilding a 70-Person Agency After Collapse and Crisis
- Episode 243: Stephen Wilson Downey – The New Playbook: GEO, E-E-A-T, Signals & Being “The Answer”
