From Startup to Global Cybersecurity Company, ThreatLocker
Cybersecurity company ThreatLocker has grown from a small startup into a global technology firm employing more than 700 people.
Founded by entrepreneurs Danny Jenkins and Sami Jenkins, the company built its platform around a strict deny-by-default security model commonly described as Zero Trust. Instead of trying to detect cyber threats after they appear, the system blocks unauthorised software from running in the first place.
Speaking at the company's sixth Zero Trust World conference in Orlando, ThreatLocker's leadership outlined how this approach has driven the company's rapid growth and international expansion.
Danny Jenkins says the philosophy behind the platform is intentionally simple.
"We just figure out what needs to run on a system and allow that to run perfectly," he said. "Everything else is irrelevant. It doesn't need to be there."
This principle, allowing only what is explicitly approved to run, sits at the core of the company's platform.
A Different Approach to Cybersecurity
Traditional cybersecurity tools attempt to detect malicious behaviour or known threats. ThreatLocker takes a different approach by blocking everything by default and allowing only approved applications to run.
The aim is to prevent ransomware and other attacks before they can execute.
Jenkins believes the cybersecurity industry sometimes overcomplicates the problem.
"Everyone wants to think there's some kind of magic formula," he said. "But it's simple. You create a really good product that solves a real problem and then you make sure people understand what it does."
Seamus Lennon, Vice President of Operations for EMEA at ThreatLocker, says the model reverses how many traditional security systems operate.
"For the past twenty years security tools have tried to stay one step ahead of attackers," he said. "With a deny-by-default model you allow only what is required and block everything else."
From IT Services to Cybersecurity Platform
The idea behind ThreatLocker emerged from the founders' earlier work running IT services and security businesses.
While managing IT systems for customers during the 2010s, Danny and Sami Jenkins repeatedly saw ransomware and malware bypass existing security tools.
Sami Jenkins said the product grew directly from that experience.
"We were running IT management services and kept seeing the same issue," she said. "We looked for products that could solve it but couldn't find anything that worked the way we needed. So the only solution was to build one."
Development began in 2015 and the first version of the platform was released in 2017.
In the early stages the company consisted of only a handful of people working on the product. Today it has grown into a global cybersecurity company employing more than 700 staff.
Sami remembers the financial risk involved in building the business.
"We basically went bankrupt building this company," she said. "Credit cards and everything went into it. So it's very rewarding now to see the impact it has."
Irish Roots in the Company's Story
Ireland also played an early role in the story of ThreatLocker.
Sami Jenkins, whose maiden name is Samantha Yorke, grew up in County Meath close to the border with County Cavan. She met Danny Jenkins while he was working in the nearby town of Kingscourt, and the two entrepreneurs went on to build several technology businesses together.
"We met in Kingscourt," she said, and their partnership developed from there.
Before founding ThreatLocker, the pair established and later sold two earlier technology businesses, including ventures in email security and IT management services. Their work supporting IT systems for customers ultimately led to the development of the ThreatLocker platform.
Why Organisations Adopt the Platform
ThreatLocker's customers include large enterprises, managed service providers and organisations in sectors such as finance, manufacturing and healthcare.
Many organisatio...

Inside ThreatLocker's Rise from Startup to Global Cybersecurity Company