A recent Cloudflare outage offered a powerful, real-world demonstration of Rust's safety guarantees. The incident was traced to a runtime error in legacy Lua code—a bug that Rust's compiler would have prevented.

As more companies migrate critical services, will Rust's compile-time checks become the new standard for preventing these kinds of costly, high-profile failures?

In today’s Rust recap:

> Cloudflare outage highlights Rust's real-world safety benefits

> Rust's core library receives safety certification

> CPython core developers propose Rust integration

> Compiler team delivers faster builds

Cloudflare's Crash Course

The Recap: A major Cloudflare outage was traced to a bug in its legacy Lua-based WAF, an issue that comes just weeks after a similar widespread incident. In a dramatic, real-world example of Rust's safety guarantees, the company's new Rust-based proxy architecture was completely unaffected by the bug.

Unpacked:

  • The outage was caused by a classic runtime error in Lua—an attempt to index a nil value—that had gone undetected in the legacy codebase for years.

  • The change that triggered the failure was part of an effort to protect users from a critical React vulnerability, showing how even well-intentioned patches can have unintended consequences.

  • Cloudflare explicitly noted that its new proxy, written in Rust, was not vulnerable because Rust's strong type system prevents this entire class of error at compile time.

Bottom line: This incident serves as a powerful case study for adopting Rust in critical, large-scale infrastructure. The language's compile-time safety checks can prevent costly outages that dynamically-typed languages might miss.

Rust Gets Safety Certified

The Recap: Ferrous Systems has formally certified a subset of Rust's core library through its Ferrocene toolchain. This move opens the door for Rust adoption in safety-critical industrial, automotive, and embedded systems.

Unpacked:

  • The IEC 61508 (SIL 2) certification specifically targets no_std environments, providing a validated foundation for firmware and real-time software.

  • The certified core subset gives developers access to essential building blocks like Option, str, slices, and other key primitives.

  • This isn't just theoretical; the certified toolchain is already in use for industrial robotics and in mining, where Kiteshield is developing a collision-avoidance system.

Bottom line: This certification removes a major formal barrier, positioning Rust as a viable and memory-safe alternative to C and C++ in regulated industries. It provides a trusted foundation for building the next generation of high-reliability software.

Python's Rust Moment

The Recap: A new proposal from two CPython core developers to integrate Rust into Python's reference implementation has ignited discussion. This signals a potential shift toward using Rust for performance-critical and memory-safe modules within one of the world's most popular language ecosystems.

Unpacked:

  • The plan aims to leverage Rust to build safer, performance-critical modules, citing evidence from efforts like Rust in Android that show a reduction in security vulnerabilities.

  • The idea has drawn support from key figures like Python creator Guido van Rossum and PyO3 project maintainers, who see it as a way to attract new contributors.

  • In response to community feedback about build complexity and platform support, the proposers have scaled back the plan to focus on optional modules for now.

Bottom line: Even with a more gradual approach, this conversation marks a significant milestone for Rust's influence in major language ecosystems. It validates the language's strengths in safety and performance on one of software's biggest stages.

Compiler Gets Quicker

The Recap: A detailed review of recent Rust compiler performance work reveals significant speedups, continuing the progress from a May 2025 update. The latest gains come from an upgrade to LLVM 21, query system optimizations, and more efficient proc macro code generation, resulting in faster builds for everyone.

Unpacked:

  • The compiler's upgrade to LLVM 21 delivered a mean instruction count reduction of 1.7%, providing a broad performance boost across most compilations.

  • Optimizations to Bevy's #[derive(Reflect)] macro reduced its generated code size by 39%, leading to a 16% faster cargo check for the bevy_window crate.

  • A new experimental flag, -Zhint-mostly-unused, now offers major compile-time wins for projects using small parts of large API crates like windows or rustix.

Bottom line: These targeted improvements show how the compiler team is enhancing the daily developer experience. Continuous performance work is essential for offsetting the cost of new language features and keeping Rust productive.

The Shortlist

Tor shipped version 1.8.0 of Arti, its Rust-based client, introducing smarter circuit timeouts to reduce traffic analysis fingerprinting and advancing progress toward full relay support.

Redox achieved a major milestone by porting a Wayland compositor, the WebKitGTK browser engine, and the MATE desktop to the Rust-based operating system.

Crates.io removed two malicious crates, finch-rust and sha-rust, after a security team discovered they were typosquatting an existing crate to exfiltrate user credentials.

Feather released a major update to its Express.js-inspired web framework, featuring a completely rewritten runtime, full multithreading support, and significant performance gains.