Petr Chmelar has been building network threat detection technology for over 15 years. His previous company, GreyCortex, developed network traffic analysis (NTA) tools used by enterprise security teams [LinkedIn]. Now, his new venture is targeting the other end of the market. Founded in 2023, Berlin-based Resistine is building what it calls an AI-powered XDR (extended detection and response) assistant, delivered as a service [Perplexity Sonar Pro Brief]. The bet is straightforward: small and medium-sized enterprises lack the budget and expertise for complex security stacks, so give them the core capabilities through a simple chat or email interface [Perplexity Sonar Pro Brief].
The Founder's Wedge
The company's strategy is linked to its founder's background. Chmelar is a repeat founder whose public profile is built on deep technical work in network security, having invented GreyCortex's core NTA technology [LinkedIn]. The product concept centers on conversational interfaces powered by large language models and open-source security tools [Perplexity Sonar Pro Brief]. The goal is to unify prevention, detection, and response across endpoints, cloud, and networks into a single, affordable service [RocketReach]. The company has also backed this with open-source contributions, including a guide and tools like a macOS version of the ClamAV antivirus engine [GitHub].
The Early-Stage Reality
Resistine's current position is that of a very early-stage venture. It participated in the Founder Institute accelerator program in Germany [Founder Institute]. Public traction signals are minimal. There are no disclosed funding rounds, named investors, customer logos, or open job postings [Perplexity Sonar Pro Brief]. Its social media presence is quiet. This places the company firmly in the build-and-validate phase, with its GitHub activity serving as the primary public indicator of technical development [GitHub].
What Comes Next
The path forward hinges on a few critical, unanswered questions. Can the LLM-and-open-source stack deliver enterprise-grade security outcomes reliably? Will SMEs trust a chat-based assistant with their crown jewels? And, fundamentally, can the company attract the capital needed to build out the robust backend and go-to-market engine required to compete? As a pre-seed company with an undisclosed round, the next 12 months will be about moving from technical prototype to validated product. The founder's pedigree in network threat intelligence is a solid foundation, but the leap from building detection algorithms for specialists to serving generalist business owners is a significant one.
Sources
- [RocketReach] Resistine Information | https://rocketreach.co/resistine-profile_b73a1e7ac7fc0065
- [LinkedIn] Petr Chmelar Profile | https://www.linkedin.com/in/chmelarp/
- [GitHub] Resistine GitHub Organization | https://github.com/Resistine
- [Founder Institute] Founder Institute Germany | https://founderinstitute.berlin/