Microsoft’s Bold Goal: Replace 1b Lines Of C/c++ With Rust

Microsoft is hiring top-level engineers to thief to get free of C and C++ successful its largest codebases and switch that codification pinch Rust.

In a job listing station connected LinkedIn, Galen Hunt, distinguished technologist astatine Microsoft, wrote: “My extremity is to destruct each statement of C and C++ from Microsoft by 2030.”

In responding to questions from commenters astir why Rust and not another (more familiar) connection for illustration C#, Hunt mentioned representation information and concurrence.

“Two reasons for Rust complete C#: 1) C# is representation safe, but not concurrent safe, 2) capacity (no GC). Just astatine Microsoft, we person astir a cardinal lines of codification that I want to [be] rewritten,” he wrote. “Across nan industry, it is astir apt 20-40BLoC that needs to beryllium written.”

How Will They Do It?

Hunt said Microsoft will harvester AI and algorithms to rewrite Microsoft’s largest codebases.

“Our North Star is ‘1 engineer, 1 month, 1 cardinal lines of code,’” he wrote.

Hunt described nan process arsenic “previously unimaginable.” However, nan institution has built a powerful codification processing infrastructure to grip it.

“Our algorithmic infrastructure creates a scalable chart complete root codification astatine scale,” he wrote. “Our AI processing infrastructure past enables america to use AI agents, guided by algorithms, to make codification modifications astatine scale.”

Moreover, this infrastructure is already operating astatine standard connected problems specified arsenic code understanding.

Joining nan Team

Hunt emphasized nan value of a diverseness of skills connected his team.

“We return connected bold risks,” he wrote.

“Our squad is driven by a maturation mindset. We are a divers squad pinch a wide scope of skills and perspectives,” Hunt wrote. “We person learned that our diverseness and maturation mindset is captious to occurrence successful nan quickly changing world of AI-based tools.”

Hunt is hiring a Principal Software Engineer to thief Microsoft germinate and augment its infrastructure to alteration translating Microsoft’s largest C and C++ systems to Rust.

“A captious request for this domiciled is acquisition building production-quality systems-level codification successful Rust — preferably astatine slightest 3 years of acquisition penning systems-level codification successful Rust,” Hunt said. “Compiler, database aliases OS implementation acquisition is highly desired. While compiler implementation acquisition is not required to apply, nan willingness to get that acquisition successful our squad is required.”

Hunt’s squad is portion of nan Future of Scalable Software Engineering group successful nan EngHorizons statement successful Microsoft CoreAI, he wrote.

“Our ngo is to build capabilities to let Microsoft and our customers to destruct method indebtedness astatine scale,” he said.

The Gradual Move To Rust

Microsoft has been signaling its gradual move to Rust for immoderate clip now.

As acold backmost arsenic 2022, Mark Russinovich, Microsoft Azure CTO, posted connected X, formerly known arsenic Twitter, that “it’s clip to halt starting immoderate caller projects successful C/C++ and usage Rust” for scenarios wherever a non-GC connection is required.

In addition, astatine nan RustConf 2025 convention successful September, Russinovich said astir really Rust was helping Microsoft hole information issues pinch Windows, among different things.

C and C++ fto you constitute codification that looks good but crashes spectacularly or, worse, gets hacked, he indicated. Microsoft’s ain kernel has been leaking privilege escalation bugs monthly done Win32k.sys, nan portion that handles graphics and windows, Russinovich said.

During his keynote astatine RustConf 2025, “From Blue Screens to Orange Crabs: Microsoft’s Rusty Revolution,” Russinovich described nan business arsenic being for illustration “an underground lipid repository that is leaking lipid up a fewer drops astatine a time, conscionable consistently.”

So nan institution started rewriting chunks successful Rust. Not nan full thing, conscionable pieces. If you excavation into your Windows System32 files correct now, you’ll find a record called win32kbase_rs.sys. That’s Rust codification moving successful your kernel.

Here’s nan point that really matters: When a information interrogator recovered a bug successful nan caller Rust version, it collapsed nan strategy alternatively of letting an attacker return over, Russinovich said.

“This we position arsenic a success,” he said. “This codification written successful C++, this bug would person really resulted successful a imaginable elevation of privilege, arsenic opposed to a bluish surface clang that’s very deterministic and can’t beryllium exploited.”

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