Microsoft engineers have quietly moved a strategy conversation about language choice into an explicit, time‑boxed program: to
eliminate C and C++ from Microsoft’s core codebase by 2030 by using algorithmic program analysis combined with AI agents to translate and re‑engineer legacy systems into Rust.
Background
Microsoft’s interest in Rust is not new. The company began introducing Rust into Windows and Azure projects in pilot form during 2023 and 2024, citing memory‑safety and maintainability as primary motivations. Senior engineering leaders have publicly endorsed Rust for new kernel and systems work, and early internal experiments — including kernel‑adjacent components and portions of the graphics/font stacks — produced measurable evidence that Rust can meet performance and reliability expectations.
What changed in late 2025 is the publicness and scale of the ambition. A LinkedIn recruitment post from Distinguished Engineer Galen Hunt lays out a concrete, audacious north star: remove every line of C and C++ from Microsoft codebases by 2030, and build the tooling and AI infrastructure to make that possible. The job ad describes a CoreAI team called
Future of Scalable Software Engineering (EngHorizons) whose charter is to build algorithmic graph representations of massive source trees and to orchestrate LLM‑driven agents that perform large‑scale transformations under algorithmic guidance. The post also frames productivity goals in stark terms — the oft‑quoted “one engineer, one month, one million lines” metric — as a guiding throughput target rather than a literal staffing rule.
This shift is strategic as much as technical: Microsoft sees Rust as a way to
reduce classes of memory‑safety vulnerabilities, lower long‑term maintenance costs, and apply modern toolchains and verification to a codebase that spans hundreds of millions of lines accumulated over decades. The public narrative ties the plan to mitigating the memory‑safety problems that historically generated a large share of Microsoft’s security patches.
What Microsoft has said — and what’s verifiable
The core claims in plain language
- A CoreAI team (EngHorizons, “Future of Scalable Software Engineering”) is hiring senior systems‑level Rust engineers and compiler/OS experts to build large‑scale code‑processing infrastructure. The role requires on‑site Redmond work.
- Galen Hunt’s posting explicitly states the 2030 objective: to eliminate “every line of C and C++ code from Microsoft.” The post describes an integrated strategy of algorithmic program analysis + AI agents for code translation and large‑scale refactoring.
- Microsoft has previously announced Rust pilots inside Windows (including kernel experiments) and reported results such as a partial rewrite of DirectWrite and other small kernel items used as proof‑of‑concepts. Public comments from Microsoft engineers in 2023–2024 confirm Rust is being used for new kernel work.
Verifiable artifacts cited in public material
- The LinkedIn job post and team description from Galen Hunt are public artifacts that explicitly describe the programmatic goal and tooling approach.
- Microsoft published a formal support advisory (KB5072911) documenting a Windows 11 provisioning/XAML registration race condition that affected enterprise provisioning scenarios in mid‑to‑late 2025. This operational incident is frequently referenced in public discussion as context for urgency on system reliability and verification.
Why Rust — the technical and security case
Memory safety and class reduction
Rust’s ownership and borrow checker model enforce memory and data‑race safety at compile time without a garbage collector, which is precisely the property Microsoft wants for low‑latency, system‑level code. Historically, memory‑safety bugs — buffer overflows, use‑after‑free, and heap corruption — drove a large fraction of Windows security patches. Microsoft has cited the high portion of memory‑safety fixes as a driver for adopting safer languages in kernel and cloud code. Migrating high‑risk modules to Rust reduces the
density of vulnerability classes in future development.
Maintainability, toolchain, and long‑term cost
Beyond security, Rust offers a modern package and tooling ecosystem (Cargo, crate registries, integrated static analysis paths) that can make long‑term maintenance and cross‑module refactoring more consistent. Microsoft frames the program not only as an internal rewrite but as a strategic capability to
eliminate technical debt at scale using reproducible algorithmic processes and AI assistance. If successful, the migration could lower triage and investigation costs for memory‑corruption incidents and, over the long run, reduce maintenance overhead for systems code.
The proposed approach: AI + algorithms, not magic
The publicly stated plan separates the effort into two technical pillars:
- Algorithmic infrastructure: build whole‑program graphs and scalable program representations that encode control/data flow, ABI contracts, and cross‑module dependencies. This layer is intended to enable deterministic, compiler‑grade reasoning about semantics and interfaces.
- LLM/AI agents: use language models as assistants — for skeleton translation, idiomatic Rust repair, and guided refactoring — orchestrated by the algorithmic layer and connected to iterative compile/test/verify loops. The aim is to reach high‑throughput mechanical translation while preserving behavioral equivalence as far as possible.
This hybrid approach maps to plausible academic and industrial prototypes: rule‑based transpilers produce mechanically correct but often unsafe Rust, LLMs can provide idiomatic fixes and contextual repair, and static analyzers + fuzzers can validate the resulting artifacts. Microsoft’s hiring descriptions emphasize a willingness to combine compiler expertise, systems programming, and machine learning to operationalize these pipelines.
Strengths of Microsoft’s plan
- Scale and resources: Microsoft has the compute footprint, engineering headcount, and testing infrastructure (including canary/insider rings) to attempt migrations at orders of magnitude larger than typical open‑source experiments. That enables pragmatic staged rollouts and broad QA telemetry.
- Concrete pilot experience: Internal Rust pilots in Windows and Azure give the company a living testbed for build, packaging, and deployment patterns (Cargo↔MSBuild interop, driver/ABI shims). These pilots reduce exploratory risk when moving to larger targets.
- Security payoff potential: If high‑risk subsystems (storage, networking, drivers, graphics) migrate successfully, the long‑term exploit surface for memory‑corruption attacks can shrink materially. This provides tangible returns for enterprise customers and cloud reliability.
- Organizational alignment: Public job postings and senior leadership comments create an incentive alignment across product groups and hiring priorities that can accelerate skill development and tooling cross‑pollination.
Real, practical risks and limitations
1) Semantic equivalence is subtle and costly
Converting C/C++ code that relies on undefined semantics, custom allocators, inline assembly, platform intrinsics, and nuanced ABI assumptions is not a mechanical text‑rewrite problem. Behavioral equivalence requires deep analysis, test coverage, and often human design decisions about ownership models and lifetime boundaries. Automated translation can shrink the labor bar but cannot eliminate careful verification.
2) New failure modes and operational risk
Language changes alter failure modes. For example, converting certain classes of memory corruption into deterministic panics or crashes can be safer from an exploitation standpoint but still impact reliability. Microsoft’s operational history with servicing incidents (e.g., the Windows 11 XAML provisioning race documented in KB5072911) highlights that
non‑memory lifecycle and timing bugs remain a major source of customer‑visible regressions; those are
not solved by Rust alone. Over‑reliance on automation, without exhaustive staged verification, risks high‑impact regressions at scale.
3) ABI and third‑party ecosystem
Windows and Azure rely on a vast ecosystem of drivers, firmware, ISVs, and OEM integrations. Ensuring ABI compatibility, reproducible builds, and signed firmware flows across this ecosystem is a major coordination and legal/IP task. Some legacy components may never be easily translatable without vendor cooperation or architectural rework.
4) Tooling and verification gaps
LLM‑assisted translation is promising but currently brittle for deep systems work. The plan depends on robust static analysis, formal checks, model‑guided repair, and high‑coverage test harnesses. Achieving production‑grade trust in automated transformations requires transparent verification artifacts, reproducible datasets, and independent audits — all of which Microsoft will need to publish (or at least internalize rigorously) to maintain enterprise trust.
5) Human and organizational friction
Eliminating “every line” of C/C++ is also a human problem: knowledge, design intent, and historical assumptions are embedded in code. Rewrites risk losing that tribal knowledge unless paired with thorough documentation, developer reskilling, and institutional review. The timeline compresses the window for careful, iterative migration and raises the possibility of cultural pushback and talent scarcity for systems‑level Rust expertise.
Practical roadmap Microsoft could (and appears to) follow
- Inventory and prioritize code by risk (security CVE history, incident frequency, customer impact).
- Pilot conversions for well‑scoped subsystems with excellent test coverage (fonts, graphics, storage drivers).
- Build hybrid translation pipelines: rule‑based skeletons → LLM‑guided idiomatic repair → compile/test/verify loops.
- Deploy translated modules behind feature flags and insider rings with extra telemetry and rollback mechanisms.
- Expand interop layers and ABI shims to allow mixed Rust/C++ operation without wholesale replacement.
- Publish verification artifacts and tooling where possible to attract ecosystem validation and reduce proprietary‑only trust barriers.
Readiness signals and what to watch
- Continued hiring velocity for systems‑level Rust, compiler, and verification engineers in Redmond and related hubs.
- Public releases or whitepapers describing the algorithmic graph infrastructure, compile/test/verify loops, or Cargo↔MSBuild tooling.
- Measured security outcomes: a demonstrable decline in memory‑safety CVEs attributable to migrated components over multi‑year timelines.
- Staged rollouts into business‑critical channels with telemetry and canaries that are transparent about failure rates and mitigations.
Community reaction — technical pushback and nuance
The declaration has polarized developer communities. C and C++ proponents correctly note that
well‑written C++ can be safe and maintainable in expert hands, and that replacing language does not automatically create perfect software. Others emphasize that Rust is not a magic bullet — problems like resource exhaustion, architecture flaws, and timing/race conditions are orthogonal to memory safety and must be addressed via engineering practices and test strategy rather than language choice alone. Microsoft’s public framing acknowledges this nuance by combining algorithmic verification with translation, but critics warn that the plan's timeline and reliance on AI raise real execution concerns.
What is (and isn’t) verifiable today
- Verifiable: Galen Hunt’s public hiring post describing the 2030 objective and tooling approach, and Microsoft’s prior Rust pilot experiments inside Windows and Azure.
- Verifiable: Microsoft’s Windows 11 provisioning/XAML advisory (KB5072911), which is cited as context for operational pressures and the need for stronger verification.
- Not yet independently verifiable: That every line of C/C++ across Microsoft products will be eliminated by 2030 for certain. The job posting is a strong signal of intent and a real internal program charter, but achieving full removal company‑wide encompasses legal, ecosystem, and product lifecycle actions that will require years of staged evidence and external validation. Treat the 2030 date as a declared target that will be measurable by future milestones — not as an already‑completed plan.
Practical guidance for IT teams and enterprises
- Treat large‑scale language migration as an engineering program, not a policy checkbox. Prioritize risk‑driven migration where possible.
- Demand transparent verification: telemetry, tests, fuzzers, and independent audits before adopting translated modules in production fleets.
- Prepare for mixed‑language stacks for years: expect ABI shims, interop tooling, and mixed runtime environments as the practical path forward.
- Increase investment in test harnesses and fuzzing for high‑risk subsystems today — those investments pay off whether code is in C/C++ or Rust.
Conclusion
Microsoft’s public move to operationalize a company‑scale Rust migration using algorithmic program analysis and AI agents is one of the most consequential engineering experiments of the decade. The technical logic — reduce memory‑safety vulnerabilities, modernize toolchains, and attack technical debt programmatically — is coherent and supported by pilot evidence. The company’s scale gives the program a credible shot at making measurable impact.
At the same time, there are deep engineering and organizational challenges: guaranteeing semantic equivalence, preserving ABI contracts, coordinating an enormous third‑party ecosystem, and avoiding new classes of operational risk introduced by automation and rapid change. The 2030 horizon is audacious and useful as an investment and hiring signal; whether it becomes a measured, validated transformation or an aspirational leadership statement will depend on the next phases of tooling publication, independent verification, staged rollouts, and transparent telemetry.
For Windows and Azure administrators, the prudent posture is clear: follow Microsoft’s progress, demand reproducible verification for any translated components you deploy, and continue to invest in testing and defensive engineering practices that reduce risk regardless of language choice. The migration is not an instant fix — it is an era of systems‑level engineering, toolchain evolution, and a test of whether AI plus classical program analysis can reliably reshape foundational infrastructure at hyperscale.
Source: 36Kr
Microsoft Bids Farewell to C++ Once and for All: Initiates Biggest Code "Demolition" as Windows and Azure to be Rewritten in Rust