Fastly

Fastly is best known as an edge cloud and content delivery network operator, but its security line — Fastly Next-Gen WAF — is a substantial, distinct product business built around web application firewall, runtime application self-protection (RASP), API security, bot management, and rate limiting. The product traces to Fastly’s $775 million acquisition of Signal Sciences in 2020, which the company folded into its edge network to inspect and block malicious traffic close to the request origin rather than relying on a bolted-on legacy WAF appliance.

Founded in 2011 and headquartered in San Francisco, Fastly went public on the NYSE in 2019 (ticker: FSLY) and has since built its security portfolio into a meaningful share of overall revenue alongside its core CDN and compute business. The company reported roughly 1,140 employees as of the end of 2025.

As a public infrastructure company operating at internet scale, Fastly brings operational credibility that pure-play application security startups typically cannot match — its WAF inspects traffic across a network built to handle some of the internet’s largest content and API workloads. It competes against both dedicated WAF/bot vendors (Cloudflare, Akamai, Imperva) and the security add-ons of other CDN platforms, and its security business is best understood as a well-integrated extension of its infrastructure footprint rather than an independent security-first product line.