Rust is a systems programming language that aims for performance, safety, and concurrency without relying on a garbage collector.
We are starting a new course on the web, and this time we are entering high-performance territory.
Rust has been standing out in developer surveys for years and is increasingly appearing in more systems projects. Even the Linux kernel incorporates support for writing certain components in Rust.
What is so special about it? Why all the fuss about a systems language? In this introductory post, we will look at what Rust is, what problems it tries to solve, and why it is worth learning.
What is Rust?
Rust is a multi-paradigm systems programming language, designed by Mozilla Research, that focuses on three objectives that were traditionally difficult to achieve simultaneously: safety, speed, and concurrency.
Historically, in software development we had to choose:
- High-level languages (Python, JavaScript, C#): Very safe and quick to write, but with a Garbage Collector (GC) that manages memory for us, sacrificing performance and control.
- Low-level languages (C, C++): Full hardware control and maximum performance, but with manual memory management that opens the door to serious errors (blue screens, memory leaks, security vulnerabilities).
Rust tries to break that dichotomy. It offers us performance comparable to C and C++ with memory safety guarantees, and it does so without using a garbage collector.
Rust achieves memory safety at compile time through a system of Ownership and Borrowing. If the code compiles, it is (almost certainly) safe in terms of memory.
The Three Promises of Rust
Rust is fast. Very fast. By not having a garbage collector (GC) running in the background, the compiled code is as efficient as C or C++.
Its philosophy of zero-cost abstractions also stands out. High-level features like iterators or closures are designed to be optimized without adding an inherent penalty compared to equivalent manual code.
The Rust compiler (based on LLVM) does a brutal optimization job.
Memory safety is one of the main reasons to look fondly at Rust. In languages like C++, it is the programmer’s responsibility to remember to free memory (free or delete). If you forget: memory leak. If you free it twice: double free. If you access it after freeing it: use after free.
Rust eliminates these errors at compile time. It has a component called the Borrow Checker that analyzes your code and ensures that invalid references never exist.
The Rust compiler is strict, sometimes even “annoying.” But it is a strict friend: it prevents you from making mistakes that in other languages would cost you hours of debugging.
Writing multithreaded code is particularly difficult. A data race occurs when multiple threads access the same data simultaneously, at least one modifies it, and no proper synchronization exists. These are erratic errors, difficult to reproduce and fix.
Rust’s type system prevents data races in safe code. If you try to share data between threads in a way that breaks its rules, the code will not compile. However, Rust does not by itself prevent all logical concurrency errors, such as deadlocks.
Comparison: Rust vs C++
This is the inevitable comparison. C++ has been the undisputed king of systems programming for decades. Why use Rust?
| Feature | C++ | Rust |
|---|---|---|
| Memory Management | Manual, RAII and smart pointers; also allows unsafe operations. | Based on ownership and checked by the compiler in safe code. |
| Performance | Excellent. Full hardware control. | Excellent. Comparable to C++. |
| Learning Curve | High complexity due to decades of legacy. | High at the start (fighting the Borrow Checker), but smoother afterwards. |
| Modernity | Carries baggage of C compatibility. | Modern design from scratch. Clear semantics. |
| Package Management | Fragmented (CMake, Conan, vcpkg…). | Unified and excellent with Cargo. |
Let’s not fool ourselves, C++ is not going to disappear. Rust is an increasingly serious alternative for new projects where resource control and memory safety are important.
The Ecosystem: Cargo
We cannot talk about Rust without mentioning Cargo. It is, arguably, the best package manager and build tool currently in existence.
Cargo manages:
- Project creation.
- Downloading dependencies (called Crates).
- Compilation and optimization.
- Running tests.
- Generating documentation.
If you come from struggling with Makefiles or complex environment configurations, Cargo will save you a lot of suffering.
Why Should You Learn It?
Learning Rust is not just learning a new syntax. It changes the way you think about programming.
- It makes you a better programmer: Understanding Ownership and Lifetimes will make you understand how memory works better, even when you go back to writing in C# or JavaScript.
- Growing ecosystem: There are more and more libraries, tools, and real-world projects written in Rust.
- Use in systems software: The Linux kernel now accepts components written in Rust, and several large companies use it in production products.
Honest warning: Rust has a steep initial learning curve. The compiler will yell at you. You will have errors you don’t understand at first. This is normal. In this course, we will go step by step to overcome that initial barrier.
