Brian Sack joined TLV Partners at its founding in 2015 and helped shape the firm's early-stage investment strategy, bringing a three-continent perspective from his background in South Africa, Australia, and Israel. He describes himself as a disciplined generalist who applies rigorous pattern recognition across different markets and technologies to spot non-obvious opportunities, while also practicing Hebrew calligraphy as a precise counterbalance to the ambiguity of venture investing.

• Belief that the rise of artificial intelligence in software development creates an urgent need for automated testing and code review. Speeding up code creation leads to lower quality codebases and firefighting production issues. A prime example is backing Qodo, formerly CodiumAI, based on the early thesis that as codebases scale rapidly, engineering teams will lose touch with their own logic and require specialized testing platforms to maintain code integrity.
• A focus on treating artificial intelligence agent security as a fundamentally new challenge rather than an extension of legacy cybersecurity. Startups pitching in this space frequently make the mistake of applying old categories like application security or identity management to agents. Because agents operate without human emotion and consist mostly of underlying models rather than complex microservices, they require entirely new categorization and security approaches.
• Rejection of universal startup formulas and industry shortcuts. Building a company requires a tailored approach where founders try and fail multiple times to find product market fit. This is particularly relevant in the cybersecurity sector, where founders are often pitched a false narrative that success comes from following established paths rather than relying on unique ideation and targeted customer validation.
• Interest in generational shifts within specific technology verticals, particularly browser security. Examining how the market moved from earlier isolation techniques to modern embedded browser protections built by companies like Talon, Island, and LayerX. A critical part of this analysis involves evaluating external threats to these startups, such as whether native advancements in underlying technologies like Chromium will eventually make third party security tools obsolete.