Why Are JS Tools Being Rewritten in Rust?

1. Performance Ceiling in JavaScript Implementations

Tools like ESLint, Prettier, Rollup, and Webpack were groundbreaking, but they’re reaching performance limits due to:

• Single-threaded execution
• High CPU cost for AST parsing
• Increasing project size
• More complex analysis / transforms

Rust allows tool authors to:

• Use multi-threading safely
• Parse code orders of magnitude faster
• Reduce memory overhead
• Deliver predictable, stable performance

This results in tooling that is 10–100x faster, depending on the workload.

2. All-in-One Tooling Instead of Many Plugins

The older JS tools rely heavily on:

• Plugins
• Custom configs
• Babel
• Loaders
• External AST tools

This creates:

• Ecosystem fragmentation
• Slow configuration
• Slow runtime due to multi-layered parsing

Rust-based tools like Biome bundle formatting, linting, and static analysis into a single engine with zero JavaScript dependencies, reducing both runtime and maintenance load.

3. Better Safety and Predictability

Rust’s memory safety and strong type system reduce whole classes of bugs in tooling.

This leads to tools that are:

• More stable
• More predictable
• Easier to evolve
• Less prone to ecosystem-breaking updates

Biome: A Rust-Powered Linter, Formatter & Analyzer

What It Replaces

Biome aims to consolidate functionality typically spread across:

• ESLint
• Prettier
• TypeScript ESLint
• tsconfig paths tooling
• Misc formatting plugins

Biome is fast enough to perform tasks in single-digit milliseconds that ESLint might take seconds for.

Strategic Benefits

1. Single tool, single AST

Biome does one parse and uses it for:

• Linting
• Formatting
• Static analysis
• Code transformations

All without relying on the JS plugin ecosystem.

2. Zero configuration required

Biome comes with conventions baked-in, leading to more consistent codebases.

3. Near-instant feedback

It’s fast enough to run on every keypress without lag—ideal for large repositories.

4. Better TS support

Because Biome integrates TypeScript support at the core, it avoids the “dual parser” problems ESLint plugins face.

Rolldown: The Rust Successor to Rollup

Rolldown is being built by the Vite and Rollup team to solve long-standing issues with JS bundlers:

• Slow cold builds
• Slow incremental builds
• High CPU usage
• Inefficient large dependency graphs

Why Rust Helps

Bundlers benefit the most from Rust because they process enormous module graphs.

Rust’s multithreaded architecture allows Rolldown to:

• Parallelize dependency scanning
• Parse modules faster
• Cache aggressively
• Reduce memory usage for large builds

Position in the Ecosystem

Rolldown is expected to become:

• The underlying bundler for future versions of Vite
• A faster alternative to Rollup for library authors
• A potential competitor to ESBuild and SWC bundlers

Rolldown’s strategy is clear: match Rollup’s compatibility, but with Rust-level performance.

Why This Topic Matters for Us

1. Future-proofing our Development Stack

The migration of tooling to Rust is accelerating. Knowing:

• What tools are emerging
• How they differ
• What they replace

…helps us plan our projects with longevity in mind.

2. Developer Efficiency

Faster tooling directly improves:

• Build times
• Feedback loops
• Local development speed
• CI pipelines

Biome and Rolldown can cut minutes off workflows that happen dozens of times per day.

3. Reduced Maintenance Burden

JS-based tooling generally requires more:

• Plugins
• Workarounds
• Configuration
• Ecosystem management

Rust-based tools offer cleaner, more integrated experiences.

4. Smooth Adoption Path

Both Biome and Rolldown provide incremental adoption strategies, meaning we don’t need to rewrite or restructure projects to start benefiting.

Potential adoption flow:

1. Replace ESLint + Prettier → Biome (drop-in)
2. Experiment with Rolldown on libraries or build scripts
3. Adopt Rolldown when it stabilizes in the Vite stack

This ensures we stay aligned with where ecosystem maintainers are heading.

Trade-Offs & Considerations

• Biome does not support 100% of ESLint’s rules yet
• Rolldown is still early and not suitable for production in complex apps
• Rust-based tools remove plugin flexibility (which may be good or bad)
• Some teams prefer incremental migration, not full replacement

Overall, these tools are already reshaping frontend workflows, but they must be adopted thoughtfully.

Conclusion

The “Rust-ification” of JavaScript tooling represents a fundamental shift in how the ecosystem solves performance and maintainability problems.

Tools like Biome and Rolldown are leading this movement by:

• Delivering 10–100x performance improvements
• Reducing ecosystem fragmentation
• Providing safer, more maintainable foundations
• Aligning with the future direction of build tooling

For our team, monitoring and gradually adopting these tools where appropriate will keep us aligned with modern standards while improving our development speed and reliability.