"Simon has a great understanding of how to best meet our clients wherever they are on their journey to security maturity, and how Lmntrix and our partners can help," said Lmntrix CEO Carlo Minassian.
Ractliffe's previous positions include head of cybersecurity at Singtel-Optus, APAC director for Secureworks at Dell EMC, and general manager for Australasia at IBM Internet Security Systems.
He has also held senior roles at earthwave and Cabletron.
"Australia is over-reliant on overseas cyber-security solutions and providers. I hope to change the dynamic by helping to promote home-grown Australian innovation to the Australian market," he said.
"We are going to see businesses shifting quickly away from ineffective log based MSSP, SIEM and SOC legacy security services models to more dynamic and proactive systems, which is exactly where Lmntrix comes in."
Ractliffe holds a bachelor's degree in business and economics from the University of West London.