Web services are stuck choosing between safe-but-static middleware and flexible-but-risky plugins. This talk demonstrates how WebAssembly's sandboxing combines with Rust's type safety through Tower's middleware layer to break this tradeoff. You'll see the complete architecture for running untrusted code safely in production—from pattern-based routing to fuel-metered execution—with real-world examples of authentication, validation, and rate limiting as hot-swappable WASM modules. Learn when WASM middleware makes sense, how to cross the Rust-WASM boundary securely, and build truly dynamic web services without sacrificing Rust's security guarantees. Includes live demonstrations and performance benchmarks.