Rust in Startups: 3 Success Stories and Code That Works

Why are startups increasingly looking towards Rust?

If you follow the tech world, you've surely noticed: Rust has ceased to be a language for geeks and enthusiasts. Today, it is a full-fledged tool for building a business. And not just building, but achieving impressive results.

Why are startup founders, who traditionally chose Python or JavaScript, suddenly starting to look at Rust? The answer is simple: Rust provides what is critically important for a young business — reliability and speed without compromises. When every millisecond counts and bugs can cost a reputation, Rust becomes not just a choice, but a necessity.

In this article, we will analyze three real examples of startups that built their success on Rust, and look at the code that made it possible.

Story #1: Dropbox — The Magic of Synchronization in Rust

Yes, you heard that right. One of the giants of cloud storage started as a startup and still actively uses Rust. When Dropbox engineers faced the problem of file synchronization performance, they realized: Python couldn't handle it. Every change in a file required fast processing on the client side, and the overhead of garbage collection in Python led to lags.

The solution came from the world of Rust. The key component — the sync engine — was rewritten in Rust. The result: processing speed increased by 10 times, and memory consumption dropped by 50%. For a startup processing millions of files daily, this was a breakthrough.

What does this look like in code?

One of the key patterns at Dropbox is working with data streams. Here's how you can implement safe file synchronization in Rust:

use std::fs;\nuse std::io::{self, Read};\nuse std::path::Path;\n\n/// Function for safely reading a file with error handling\nfn read_file_safe(path: &Path) -> Result<Vec<u8>, io::Error> {\n    let mut file = fs::File::open(path)?;\n    let mut buffer = Vec::new();\n    file.read_to_end(&mut buffer)?;\n    Ok(buffer)\n}\n\n/// Comparing two files by content (memory safe)\nfn compare_files(path1: &Path, path2: &Path) -> Result<bool, io::Error> {\n    let content1 = read_file_safe(path1)?;\n    let content2 = read_file_safe(path2)?;\n    Ok(content1 == content2)\n}\n\nfn main() {\n    let local_path = Path::new("local_file.txt");\n    let cloud_path = Path::new("cloud_file.txt");\n\n    match compare_files(&local_path, &cloud_path) {\n        Ok(true) => println!("Files are identical. Synchronization not required."),\n        Ok(false) => println!("Files differ. Starting synchronization..."),\n        Err(e) => eprintln!("Error comparing files: {}", e),\n    }\n}

Notice: in Rust there is no null, no exceptions in the classical sense, and the ownership system guarantees you won't accidentally corrupt data in memory. For a startup where every error is a lost client, this is invaluable.

Story #2: Figma — A Web Editor That Doesn't Lag

Figma is not just a graphics editor; it's a true triumph of Rust on the web. When Figma was just starting out, they made a bold move: they wrote the server-side in Rust. Why? Because their main competitor — Adobe — had decades of optimization. Figma needed to offer something that works lightning-fast right in the browser.

Rust allowed them to create a WebSocket server with minimal latency. Every mouse movement, every click is sent to the server, processed, and returned. In JavaScript, this would lead to a huge load on the GC (garbage collector), but Rust handles it without unnecessary allocations.

Example: Multithreaded Request Processing

Here's how you can organize a thread pool for request processing in the style of Figma:

use std::sync::mpsc;\nuse std::thread;\nuse std::time::Duration;\n\n/// Structure for processing re