AWS Shield - AWS Shield is a managed Distributed Denial of Service (DDoS) protection service that safeguards web applications running on AWS.
Barracuda Web Application Firewall - Barracuda Web Application Firewall offers security and DDoS protection against automated & targeted attacks.
Reblaze - Reblaze is a cloud-native web application and API protection solution
AWS WAF - AWS WAF is a web application firewall that helps protect your web applications from common web exploits.
Imperva Cloud Application Security - Deploy your applications and data where you want. When you want. Imperva keeps them secure in the cloud, on premises, and in hybrid clouds.
ModSecurity - ModSecurity is an Open Source web application firewall developed by Trustwave's SpiderLabs.