The text emphasizes the importance of a defense-in-depth strategy in application monitoring, paralleling it with cybersecurity principles by highlighting the limitations of relying on a single method to detect failures. The text outlines a layered monitoring approach, consisting of uptime monitoring, synthetic monitoring, and deep observability, to address various types of application failures such as infrastructure issues, application logic failures, and performance degradation. This multi-layered strategy is essential for minimizing risks, improving mean time to detection and repair, and ensuring comprehensive coverage of potential failure modes. It warns against the dangers of a monitoring monoculture, advocating for a balanced approach that combines different monitoring methods to provide rapid detection, validation of user workflows, and deep diagnostic capabilities. The ultimate goal is to protect the application, maintain revenue, and uphold the brand's reputation by ensuring a seamless user experience.