A web application firewall (WAF) is a crucial part of network security architecture that inspects, sanitizes, and redacts malicious HTTP requests for applications, protecting against Distributed Denial of Service (DDOS) attacks, OWASP Top Ten security risks, and applying advanced rate limiting strategies. WAF architecture can take many forms in enterprise solutions, including on-premise data center appliances, software solutions deployed in multiple configurations, hosted SaaS platforms, and cloud native solutions. Cloud providers also offer WAF solutions that tie into their infrastructure, but these options introduce portability issues and are not well suited for multi-cloud deployment strategies. To protect APIs the cloud native way, organizations can use open initiatives such as the ModSecurity project, deploy Edge Stack API Gateway as a Kubernetes resource, or integrate next-generation WAFs like the Signal Sciences Agent to augment their infrastructure's resiliency with added security coverage.