Web application firewall adoption (late 2000s)
As e-commerce and web applications became business-critical, SQL injection and cross-site scripting attacks grew sharply. Web application firewalls emerged to inspect and filter malicious requests before they reached application servers.
Imperva, F5, and Akamai built large WAF businesses serving enterprises that needed front-line defense for public web apps.
WAFs became standard infrastructure for any organization running public web applications, and inline security inspection at the network edge became an industry norm.
Fastly's AI Firewall adapts the WAF concept to large language models: it inspects prompts at the edge for injection attacks before they reach the model.
