Visonys was founded in 2002 with the mission to significantly improve the security of web applications on the internet, particularly to protect sensitive information and transactions for financial and telecommunications institutions. The company transformed advanced, enterprise-grade security features—previously requiring complex custom implementations—into a standardized web application firewall and security gateway called “Airlock.” This solution controls and filters all access to web application environments, enabling companies for the first time to strategically secure their entire web application landscape.

Airlock established a new standard in web application security by combining ease of deployment with enhanced protection, user authentication, high availability, and cost efficiency.

Vi Partners invested in Visonys in 2004 and supported the company’s growth and expansion. In 2008, Austrian firewall vendor Phion acquired Visonys, and Airlock became Phion’s application security business unit. Visonys founder Cyrill Osterwalder later joined Vi Partners in 2018 as a Venture Partner.