Why We Built ALLOY in Rust

The Migration Problem

Enterprise Sitecore migrations involve processing millions of content items, each with complex relationships, versioning, and metadata. Traditional .NET-based tools struggle with:

Memory pressure: Loading large content trees exhausts available RAM
Processing speed: Sequential item processing creates bottlenecks
Error handling: Crashes during long-running jobs require full restarts

We needed something better.

Why Rust?

When we set out to build ALLOY, we evaluated several options:

Option	Pros	Cons
.NET Core	Familiar, good ecosystem	GC pauses, memory overhead
Go	Fast compilation, good concurrency	GC pauses at scale
Rust	Zero-cost abstractions, memory safety	Steeper learning curve

Rust won for three reasons:

1. Predictable Performance

Rust has no garbage collector. Memory is managed at compile time through the ownership system. This means:

No GC pauses during processing
Predictable memory usage
Better cache locality

For a tool processing millions of items over hours, this predictability is essential.

2. Fearless Concurrency

Rust’s ownership model prevents data races at compile time. We can parallelize content processing across all available cores without worrying about race conditions.

// Parallel item processing with rayon
content_items
    .par_iter()
    .map(|item| serialize_item(item))
    .collect::<Vec<_>>()

3. Zero-Cost Abstractions

High-level constructs in Rust compile down to optimal machine code. We get the ergonomics of modern programming without runtime overhead.

The Results

ALLOY benchmarks against traditional migration tools:

Metric	Traditional	ALLOY	Improvement
Parse speed	1,200 items/sec	11,000 items/sec	9x
Memory usage	8GB peak	800MB peak	10x
Total time (1M items)	14 hours	1.5 hours	9x

Memory Safety in Practice

Beyond performance, Rust’s memory safety guarantees have eliminated entire classes of bugs:

No null pointer exceptions: Option types make null handling explicit
No buffer overflows: Bounds checking is enforced
No use-after-free: The borrow checker prevents it

In 18 months of production use across dozens of enterprise migrations, ALLOY has had zero memory-related crashes.

Conclusion

Building ALLOY in Rust was one of the best technical decisions we’ve made. The initial learning curve paid dividends in reliability, performance, and maintainability.

Learn more about ALLOY or schedule a demo.