Zero-day attacks, where vulnerabilities are exploited before developers are aware of them, pose significant challenges to organizations' IT security, as evidenced by a surge in such exploits, accounting for 40% of attacks in the past decade as of 2021. Highlighted at the Black Hat 2022 conference, these attacks underscore the need for improved strategies to both prevent and respond to breaches in live applications, exemplified by the Log4Shell vulnerability. As software development accelerates, integrating security into DevOps through DevSecOps is becoming essential to address vulnerabilities more efficiently and early in the development lifecycle. This integration, alongside advanced observability tools, is crucial in identifying and mitigating zero-day vulnerabilities, especially in complex cloud-native and multicloud environments where traditional security measures fall short. The convergence of observability and runtime application security is vital for protecting sensitive data and software supply chains, as organizations face increased risks from cyberattacks in an increasingly digital world.