SaaS (Software as a Service) models are increasingly popular for businesses, with giants like Cisco and Microsoft transitioning to them for agility and competitive advantage. Key success factors for SaaS include frequent releases, product-led growth, self-service experiences, and consumption-based pricing models, all of which demand robust observability to monitor user engagement, support decision-making, and ensure service availability. Observability tools are critical for understanding user interactions with both UI and APIs, enabling data-driven decisions and enhancing user experiences. Companies like Frontegg provide essential tools for user management while other platforms like Mixpanel and Prometheus support frontend and backend observability, respectively. Observability not only aids in performance monitoring but is also vital for maintaining service reliability and tuning business models, making it an essential component of a successful SaaS strategy.