B2B SaaS is facing significant challenges due to the rise of AI and vibe coding, which allow customers to create tailored software solutions without relying on traditional platforms. The author highlights a growing trend where companies are questioning their reliance on established SaaS tools, as they can now build customized applications using user-friendly AI-powered tools. This shift is reflected in market trends; for instance, Morgan Stanley’s SaaS index has underperformed the Nasdaq by 40 points since December, and companies like HubSpot and Klaviyo have seen declines of around 30%. Executives are increasingly reluctant to renew contracts for expensive software when they can replicate functionalities at a fraction of the cost. The article emphasizes three strategies for existing SaaS companies to remain competitive. First, they need to become a "System of Record" for their customers, deeply embedding their tools within daily workflows to ensure dependency. Second, they must prioritize security and robustness, areas where vibe-coded solutions often fall short. Many companies overlook crucial security measures, leading to vulnerabilities that established SaaS platforms have already addressed over years. Finally, SaaS vendors must adapt to customer needs rather than forcing customers to adapt to them. Offering customizable solutions and simplifying user experiences can significantly reduce churn rates. The author illustrates this with a case study of a complex maintenance operations SaaS that increased usage from under 35% to over 70% by simplifying the interface and allowing for customized micro-apps. Ultimately, the author argues that AI isn't killing B2B SaaS; instead, it's the companies that fail to adapt. In a landscape where customers have grown accustomed to quick, tailored solutions, the traditional model of "build once, sell forever" is becoming obsolete. SaaS companies that can evolve by integrating user-friendly, customizable features will succeed, while those that cling to outdated practices will struggle to retain clients.