A Flask or Django process can validate forms, escape templates, and still be the first thing on the Internet that parses a hostile request. I stopped treating that as an acceptable default. Framework code is the right place for permissions and business rules. It is the wrong place to discover every injection, flood, and bot pattern, because those requests have already reached the interpreter. The decision I now make first is whether a reverse-proxy web application firewall should sit on the path in front of the app.

These product pages do not describe a Flask extension, a Django middleware class, or a Python package. They describe placement. SafeLine is a self-hosted web application firewall that filters and monitors HTTP traffic between a web application and the Internet, and blocks malicious HTTP/S traffic before it is treated as safe application input ( https://docs.waf.chaitin.com/en/home ).…