Gigamon has appointed former US Department of Defense cybersecurity leader Grant Yacomeni as chief information security officer (CISO), as the company looks to strengthen its security strategy amid growing risks associated with AI and hybrid cloud environments.
Yacomeni will report to Gigamon Chief Operating Officer Gareth Maclachlan and will lead information and product security, cybersecurity and IT operations, as well as governance, risk and compliance (GRC).
He brings more than a decade of cybersecurity and national security experience to the role, including leadership positions within the United States Intelligence Community and Department of Defense.
At the DoD, Yacomeni led enterprise security programs and 24×7 defensive cyber operations. He has also served in intelligence and cybersecurity roles with the Maryland Army National Guard and is a US Marine Corps veteran.
The appointment comes as organisations face a changing security environment driven by the rapid adoption of artificial intelligence across applications, infrastructure and business processes.
Gigamon’s 2026 Hybrid Cloud Security Survey, which canvassed more than 1,000 security and IT leaders, found 33 per cent had experienced breaches in which their AI or large language model systems were targeted during the previous year.
Maclachlan said Yacomeni’s experience operating in demanding cybersecurity environments would strengthen Gigamon’s internal security capabilities while providing customers with additional practitioner expertise.
“His experience will be invaluable as we strengthen security across Gigamon and bring an even deeper practitioner perspective to our customers,” Maclachlan said.
“As AI becomes increasingly embedded across hybrid cloud infrastructure, security, resilience, and business risk are becoming more interconnected.”
As CISO, Yacomeni will focus on managing cyber risk while enabling Gigamon to continue developing and operating its technology securely. He will also work with customers and industry leaders on security strategies for increasingly complex hybrid cloud environments.
Yacomeni said the speed and scale at which AI systems can act on information was raising the stakes for security teams.
“Security teams need trusted visibility into how data, applications, and AI systems interact so they can make better-informed decisions,” he said.
“I look forward to applying that principle inside Gigamon and working with customers as they evolve their security strategies for the Hybrid AI era.”
Gigamon provides deep observability technology designed to give organisations visibility into data moving across hybrid cloud environments. The company says its technology is used by more than 4,000 organisations worldwide, including 83 of the Fortune 100.
