Cloud application security encompasses policies, controls, and tooling to reduce risk for applications running on cloud platforms. Key threats include weak IAM, exposed APIs, misconfigured IaC, supply-chain compromise, and insufficient logging. Foundational concepts include the shared responsibility model, zero trust with least privilege, and DevSecOps workflows that embed security into CI/CD. Seven practice areas are covered: secure development and testing, IAM, data protection, API/container/supply chain security, monitoring and incident response, patch automation, and compliance as code. CNAPP platforms are highlighted as essential for correlating signals across vulnerabilities, misconfigurations, and identities to prioritize actual exploit paths rather than isolated scanner findings. The post also covers operationalizing shift-left security at scale through platform teams, security champions, and executive sponsorship.