Microsoft may be gearing up for one of the boldest engineering transformations the software industry has seen in decades. A senior Microsoft engineer has outlined a long-term vision to eliminate all C and C++ code from the company’s products by the end of this decade, replacing it entirely with Rust. While the idea initially sounds radical, the details suggest Microsoft is already building the technical foundation to make it possible.

The plan was shared publicly by Galen Hunt, a senior engineer who has spent nearly 28 years at Microsoft. In a job-related LinkedIn post announcing an opening for a Principal Software Engineer (IC5) in Redmond, Hunt stated his goal clearly: removing every line of C and C++ code across Microsoft by 2030. The preferred replacement language is Rust, which has gained strong momentum in recent years for offering memory safety and high performance without garbage collection—qualities that are especially valuable for systems-level software.

What caught widespread attention was Hunt’s description of the team’s “North Star” metric: “one engineer, one month, one million lines of code.” This striking benchmark highlights the unprecedented scale Microsoft is aiming for. Traditionally, rewriting even tens of thousands of lines of legacy systems code can take months or years and comes with significant risk. Microsoft’s approach seeks to change that equation by combining AI agents with algorithm-driven systems capable of understanding and transforming massive codebases.

According to Hunt, Microsoft has already developed a powerful internal code-processing infrastructure to support this effort. At its core is an algorithmic system that builds a scalable graph over source code, mapping relationships and dependencies across extremely large projects. On top of this sits an AI processing layer, where AI agents perform code modifications while algorithms guide those changes to preserve correctness and structure. Hunt noted that this infrastructure is already operating at scale, particularly in code understanding—an essential prerequisite before any large-scale translation can occur.

The newly announced Principal Software Engineer role is designed to push this system further, with a focus on translating Microsoft’s largest and most complex C and C++ systems into Rust. The position is clearly hands-on and production-focused. Candidates are expected to have deep experience writing real-world, systems-level Rust code, ideally over several years. Backgrounds in compilers, databases, or operating systems are described as especially valuable, reflecting the low-level and performance-critical nature of the work.

Although compiler expertise is not required at the outset, Hunt stressed that new hires must be willing to develop it. This signals that the migration will involve more than automated syntax conversion—it will require careful rethinking of system behaviour, performance characteristics, and runtime verification.

Hunt also offered insight into the team culture driving this initiative. He described a group built around a “growth mindset,” comfortable with taking bold risks and embracing diverse perspectives. This approach, he suggested, is essential in an era where AI tools are rapidly reshaping how software is built and maintained. The broader mission is to help Microsoft eliminate technical debt at scale, rather than through slow, incremental rewrites.

Organisationally, the effort sits within the Future of Scalable Software Engineering group under Microsoft’s EngHorizons organisation, part of Microsoft CoreAI. Beyond internal use, the group aims to develop techniques that can eventually be shared across Microsoft’s product teams—and potentially influence the wider software industry.

While Microsoft has not issued a formal, company-wide directive to abandon C and C++, Hunt’s post offers a rare glimpse into how seriously the company is thinking about large-scale code modernisation and the role AI may play in shaping its future.