Why Rust Matters for Systems Programming
Systems programming has belonged to C and C++ for over four decades. Operating systems, device drivers, embedded firmware, game engines, the infrastructure layer of computing runs on languages designed in the 1970s and 1980s. But something shifted in the last few years. The Linux kernel accepted Rust as a second language in 2022. Android started shipping Rust components and saw memory safety bugs drop by 52%. AWS built its Firecracker microVM manager entirely in Rust. The debate over whether Rust belongs in systems programming is settling. The real question now is how fast the transition will happen.
What Systems Programming Actually Demands
Before understanding why Rust fits here, you need to know what systems programming actually requires. Systems software sits close to the hardware. It manages memory directly, handles interrupts, talks to peripherals, and must execute predictably under load.
That means three things are non-negotiable:
- Performance. You can't afford garbage collection pauses when managing disk I/O or processing network packets at line rate.
- Memory control. You need explicit control over allocation, layout, and lifetimes. Abstracting memory away isn't an option.
- Reliability. A crash in a web app means a user refreshes the page. A crash in an operating system kernel means everything stops.
C and C++ deliver all three. They also deliver something nobody wants: a steady stream of memory safety vulnerabilities that cost the industry billions of dollars each year.
The Memory Safety Problem That Costs Billions
Here's a number that should make every systems programmer uncomfortable. Microsoft disclosed in 2019 that roughly 70% of all CVEs in their products were caused by memory safety issues. Google reported nearly the same figure for Chrome. The Chromium team found that about 70% of their serious security bugs traced back to memory defects in C and C++ code.
These aren't theoretical risks. They're buffer overflows, use-after-free errors, double frees, and null pointer dereferences. Every one exploitable by attackers. The WannaCry ransomware attack, which caused an estimated $4 billion in global damages, exploited a buffer overflow vulnerability in Windows. The EternalBlue exploit it used had been a known class of bug for decades.
The root cause is straightforward: C and C++ give you full memory freedom and zero compile-time checks on how you use it. You can write perfectly safe C code. The language simply won't help you do it.
How Rust's Borrow Checker Fixes the Root Cause
Rust takes a fundamentally different approach to memory management. Instead of garbage collection (like Java or Go) or manual management (like C), Rust enforces a set of ownership rules at compile time.
The rules are straightforward:
- Each value in Rust has exactly one owner.
- When the owner goes out of scope, the value is dropped and memory is freed automatically.
- You can have either one mutable reference or any number of immutable references to data, but never both at the same time.
The borrow checker is the compiler component that enforces these rules. If your code violates them, it won't compile. There's no runtime overhead because all the checking happens before the program runs.
This means an entire class of bugs, use-after-free, data races, dangling pointers, simply cannot exist in safe Rust code. Not "probably won't happen." Cannot happen. The compiler guarantees it.
"Rust makes memory safety a compile-time property, not a runtime hope. That single design decision is why it belongs in systems programming."
— Lars Bergstrom, Director of Engineering, former Mozilla Rust team lead
Rust Performance Matches C and C++
A common concern is that safety must come at a performance cost. With Rust, it doesn't. Rust compiles through LLVM, the same backend used by Clang for C++. There's no garbage collector. There's no hidden runtime. You get the same low-level control over memory layout, alignment, and allocation strategies that C programmers expect.
Benchmarks from The Computer Language Benchmarks Game consistently show Rust performing within a few percent of C and C++ on computationally intensive tasks. In some cases, Rust outperforms C++ because the ownership model helps the compiler make optimizations that are unsafe to apply in C++ code.
Real companies have validated this with production workloads. Dropbox rewrote their file sync engine from Go to Rust and saw significant throughput improvements. Discord switched their Read States service from Go to Rust, eliminating latency spikes caused by Go's garbage collector. Neither company chose Rust to be trendy. They chose it because the numbers worked.
Where Rust Is Already Running in Production
Rust in systems programming isn't hypothetical. It's deployed at scale across the industry right now.
- Linux kernel. Rust support was merged in Linux 6.1 (December 2022). As of 2024, Rust drivers and subsystems are being actively developed for inclusion in the mainline kernel. The goal is to let kernel developers write new drivers without the memory bugs that have plagued the kernel for decades.
- Android. Google began using Rust in the Android Open Source Project in 2021. By 2022, new code written in memory-unsafe languages had dropped to 21% of total Android code additions, down from 76% in 2019. Memory safety bugs fell accordingly.
- AWS and cloud infrastructure. Firecracker, the microVM technology behind AWS Lambda and Fargate, is written in Rust. So are critical parts of the S3 storage backend.
- Windows. Microsoft has publicly stated they are rewriting core Windows components in Rust to eliminate entire classes of memory safety bugs at the source.
- Networking and embedded systems. Cloudflare, Linkerd, and Embassy (an embedded Rust framework) all use Rust for performance-critical network and hardware code.
The pattern is clear. Organizations where a single memory bug can be catastrophic are moving to Rust first.
Where Rust Still Has Friction
No language is perfect, and Rust has real tradeoffs worth understanding before you commit to it for a project.
The learning curve is steep. The borrow checker is unlike anything in C, C++, Python, or Java. Most Rust beginners spend weeks fighting the compiler. The "fighting the borrow checker" experience is practically a rite of passage. It gets easier, but it's a genuine time investment upfront.
Compile times can be slow. Rust's type system and borrow checking add compilation overhead. Large Rust projects can take minutes to fully compile, where equivalent C++ projects might complete incremental builds in seconds.
Some library areas are still catching up. If you need a production-grade GUI toolkit, an embedded HAL for an obscure microcontroller, or a machine learning framework, Rust may not have the package you need today. C and C++ have 40 years of library accumulation. Rust has roughly 10.
Unsafe Rust exists. When you need to do something the borrow checker can't verify, like FFI calls or direct hardware register manipulation, you write unsafe blocks. Unsafe Rust is a necessary escape hatch, but it removes the safety guarantees. Those sections need manual auditing, which defeats part of the purpose if overused.
Getting Started with Rust for Systems Work
If you're coming from C or C++, the best approach is to start with Rust's ownership model and get comfortable with the borrow checker before attempting any systems-level work. Write small programs. Let the compiler teach you. It will reject your code many times, and each rejection teaches you something about memory safety you probably got wrong in C without ever knowing it.
Once you're past that initial learning phase, systems programming in Rust opens up. You can write operating system components, device drivers, embedded firmware, network stacks, and database engines, all with compile-time memory safety guarantees that C simply cannot offer.
Start by understanding ownership and borrowing deeply. Then move into unsafe Rust and FFI for interfacing with existing C libraries. The combination of safe Rust for new code and controlled unsafe blocks for low-level interaction is how every production Rust project in systems programming works today.
The Linux kernel didn't add Rust on a whim. Neither did Google, Microsoft, or AWS. Each organization ran the same calculation: memory safety bugs are too expensive to keep writing by hand, and Rust is the only systems language that solves the problem at compile time without sacrificing performance.
Is Rust replacing C++ everywhere overnight? No. But in the domains where a single memory bug can be catastrophic, operating systems, security-critical infrastructure, embedded firmware, Rust is no longer an experiment. It's a production choice backed by some of the largest engineering teams on the planet.
If you want to feel what Rust is like without reading another article, pick one of the courses above and write your first program this week. The compiler will correct you more than any tutorial ever could. That correction process is where the real learning happens.
