Visonys was founded in 2002 with the mission to significantly improve the security of Web applications on the Internet, specifically to protect sensitive information and transactions, for example of financial and telecommunication institutions. Visonys turned advanced enterprise grade security features that otherwise required customized and complex implementation projects into the standardized Web application firewall and security gateway "Airlock". The solution controls and filters all access to web application environments and for the first-time enabled companies to strategically secure their whole web application environment.

Airlock successfully established a new standard for ease of deployment, better web application security, user authentication, availability and cost savings.

Vi Partners invested in Visonys  in2004 and helped the company further grow and deliver on its business expansion goals. In 2008, the Austrian firewall vendor Phion acquired Visonys and Airlock became the application security business unit of Phion. Visonys Founder, Cyrill Osterwalder, has since joined the Vi Partners team in 2018 as a Venture Partner.