Rust in Real Projects: 5 Cases of Companies That Switched to It

Rust in Action: Why Companies Choose This Language for Their Key Projects

When it comes to Rust, many imagine an academic language for systems programming enthusiasts. But the reality is far more interesting. Over the past five years, Rust has firmly established itself in the production environments of the world's largest IT companies. And this is not just a trend — behind every transition lie specific business metrics: reduced infrastructure costs, fewer bugs, and accelerated development.

In this article, we will analyze five real-world cases of Rust adoption, look at the code engineers write in these companies, and understand why Rust is becoming the standard for high-load systems. Let's go!

Case 1: Dropbox — Rewriting the Core of the File Manager

Dropbox is one of the first major players to bet on Rust. Their story began with pain: the main codebase was written in Python (and partially Go), but file synchronization on clients required maximum performance with minimal memory consumption.

The Dropbox team decided to rewrite the Nucleus synchronization engine in Rust. The result is impressive: speed increased by 10 times, and memory consumption dropped by 30%.

Here is what a code fragment responsible for efficient file reading in Dropbox looks like:

use std::fs::File;\nuse std::io::{BufReader, Read};\nuse std::path::Path;\n\n/// Reads a file in 64 KB chunks to minimize allocations\npub fn read_file_chunks(path: &Path) -> Result<Vec<Vec<u8>>>, std::io::Error> {\n    let file = File::open(path)?;\n    let mut reader = BufReader::new(file);\n    let mut chunks: Vec<Vec<u8>> = Vec::new();\n    let mut buffer = vec![0u8; 65536]; // 64 KB buffer\n\n    loop {\n        let bytes_read = reader.read(&mut buffer)?;\n        if bytes_read == 0 {\n            break;\n        }\n        chunks.push(buffer[..bytes_read].to_vec());\n    }\n    Ok(chunks)\n}

Why did this work? Rust gave Dropbox control over memory without a garbage collector. For client software running on user devices, this is critical — every extra megabyte of memory or CPU cycle degrades the UX.

Key Dropbox metrics after Rust adoption:

\n
• 70% reduction in synchronization time for large files
\n
• 40% reduction in the number of crashes
\n
• 25% reduction in API response time
\n

Case 2: Figma — Performance of Multiplayer Editing

Figma is a browser-based design tool that must work fast even with thousands of elements on the canvas. When the team faced the fact that JavaScript and WebAssembly did not provide the necessary performance for processing complex scene graphs, they turned their attention to Rust.

Figma engineers rewrote the futures-rs rendering core in Rust, which allowed them to process changes in real-time without lag. Here is an example of how they use Rust for efficient change tracking:

use std::collections::HashMap;\nuse serde::{Deserialize, Serialize};\n\n#[derive(Debug, Clone, Serialize, Deserialize)]\npub struct SceneNode {\n    pub id: String,\n    pub parent_id: Option<String>,\n    pub children: Vec<String>,\n    pub transform: [f32; 6], // 2D affine matrix\n}\n\n/// Incremental scene update based on changes\npub fn apply_delta(nodes: &mut HashMap<String, SceneNode>, delta: Vec<SceneNode>) {\n    for node in delta {\n        if let Some(existing) = nodes.get_mut(&node.id) {\n            existing.transform = node.transform;\n            existing.children = node.children;\n        } else {\n            nodes.insert(node.id.clone(), node);\n        }\n    }\n}

Why did this work? Rust allowed Figma to write code that runs on the cl