This talk introduces language-based security: leveraging programming languages and their type systems to enforce security policies at compile time. We’ll focus on taint analysis, a technique for tracking the flow of potentially harmful (or "tainted") data. In particular, we'll see how we can apply it statically to detect and prevent security vulnerabilities before they reach Production. Through practical examples in Java and Scala, we'll see how to model data sensitivity, propagate taint status and catch violations at compile time.

As more code is written or suggested by GenAI, the risk of subtle security flaws increases, making compiler-enforced security guarantees more valuable than ever.

By the end of the talk, you will see how language-based techniques can reduce reliance on dynamic checks and support building secure systems by construction.