Update December 24: Galen Hunt, a Distinguished Engineer at Microsoft, recently shared his ambitious vision of phasing out all C and C++ code within the company. However, he has since noted that his initial post garnered more attention than he expected, prompting him to clarify both his stance and Microsoft’s broader objectives.
In a revised LinkedIn update, Hunt emphasized that Windows will not undergo a complete rewrite in Rust with the assistance of AI. Instead, the focus is on developing technologies that facilitate smoother transitions between programming languages. He characterizes these efforts at Microsoft as a “research” initiative aimed at modernizing their codebase.
It’s worth mentioning that Hunt’s original statements were bold and open to interpretation, leading to various media interpretations. While a full refactoring of Windows may not be on the table, it is likely that Hunt and his colleagues are indeed targeting the eventual removal of all C and C++ code across Microsoft’s platforms, including the foundational elements of Windows. This endeavor may involve the use of automated tools, which some may refer to as AI, and the incorporation of Rust.
Original article, December 23:
There appears to be a movement within Microsoft to eliminate all C and C++ code by the end of the decade. Distinguished Engineer Galen Hunt has proposed a bold plan where AI and algorithms would facilitate a mass transition of codebases to Rust. The slogan encapsulating this initiative is striking: one engineer, one month, one million lines of code.
Microsoft is keen to address its technical debt through modern tooling. With decades of legacy code primarily written in C and its derivatives, the company aims to replace this outdated code to mitigate a specific class of vulnerabilities: memory-related bugs. Global authorities have long urged tech companies to prioritize memory safety in their development roadmaps, advocating for the adoption of Rust, a low-level language known for its memory safety features.
In its commitment to tackling technical debt, Microsoft is leveraging advanced tooling. The company has established a robust infrastructure for code processing that integrates AI agents with algorithmic analysis, which is already operational at scale for challenges such as code comprehension, as noted by Hunt on LinkedIn.
Urgency for memory-safe code
This initiative is not a spontaneous reaction to external cybersecurity warnings. Earlier this year, Microsoft announced plans to rewrite portions of the Windows kernel in Rust, following Azure CTO Mark Russinovich’s directive to halt new C/C++ projects. Russinovich declared that Microsoft was “all-in on Rust,” a sentiment that has since been reflected in the company’s expanding use of this memory-safe programming language.
The rationale behind this shift is clear: memory errors in C and C++ account for an estimated 70 percent of vulnerabilities in Microsoft products. Rust addresses these issues by incorporating memory safety without compromising performance. While it is still possible to create memory leaks in Rust, the likelihood is significantly reduced compared to C and C++. When utilized correctly, Rust offers immunity to memory safety concerns.
Russinovich previously indicated that Microsoft was pursuing “more automated translation from C and C++ to Rust using LLMs.” Hunt’s recent LinkedIn post serves as a tangible follow-up to this initiative, as he actively seeks a Principal Software Engineer to help realize these ambitious goals.
Job opening requires Rust expertise
The job listing specifies that candidates should ideally possess a minimum of three years of experience in writing systems-level code in Rust. Experience with compilers, databases, or operating system implementations is highly desirable. Although compiler experience is not a strict requirement, the selected candidate must be prepared to develop that expertise within the team.
Hunt’s Rust refactoring team operates under the Future of Scalable Software Engineering group within Microsoft CoreAI’s Engineering Horizons organization. Their mission is to “build capabilities that enable Microsoft and our customers to eliminate technical debt at scale.” The team collaborates with internal clients and partners to develop new tools and techniques, which are subsequently deployed across the company and the industry.
Rust adoption is growing worldwide
Microsoft’s commitment to Rust aligns with a broader trend of increasing adoption of the language. According to JetBrains, there are currently 2.3 million developers using Rust, with 709,000 identifying it as their primary programming language. In enterprise settings, adoption has surged by 68.75 percent. In system programming, Rust’s market share rose from 1.05 percent in 2024 to 1.47 percent in 2025, reflecting a relative increase of 40 percent. While Rust is more complex than languages like Python and lacks the extensive experience of programmers familiar with C and C++, its low-level nature minimizes abstraction layers, making it suitable for critical systems such as kernels, IoT devices, and system drivers.
Major tech companies like Google, Amazon, Dropbox, and Cloudflare are increasingly integrating Rust into their critical infrastructure. Notably, Google invested million in the Rust Foundation to enhance interoperability between C++ and Rust. This interplay between legacy and modern languages has sparked some friction in Linux kernel development, as seasoned developers accustomed to C and C++ may resist adapting to Rust. The Rust project itself faces its own set of challenges, but as tech giants continue to adopt it, the stability of core IT infrastructure becomes ever more crucial.
