Building CLI Tools: Go vs Rust

Choose CLI tool language.

Go

Go and Rust are both popular for CLI tools. Each has strengths; the choice depends on the tool's requirements. Most CLI tools fit Go; performance-critical tools may benefit from Rust.

What Go provides:

• Fast compile.: Go's compile speed is dramatically faster than Rust's. The iteration loop for development is faster; the team's productivity is preserved.
• Simple deployment.: Go produces single statically-linked binaries. The binary works on the target system without additional dependencies; deployment is bounded.
• Single binary.: No runtime dependencies. The binary is the program; copy it to the target; it runs. The deployment story is simple.
• Best for ops tools.: Operations tools often need fast iteration. Go's fast compile and simple deployment match the operational use case; the productivity is real.
• Need fast iteration.: Tools that change frequently benefit from fast compile. The engineer's edit-build-test cycle is fast; the productivity is preserved.
• Strong cloud ecosystem.: Many cloud SDKs are Go-first. AWS SDK, GCP libraries, Kubernetes client all are first-class in Go; the integration is smooth.

Go is the right choice for most CLI tools. The productivity advantages are real for typical ops tools.

Rust

Rust offers different trade-offs. Slower compile but faster runtime; more complexity but more safety. The trade-offs fit specific use cases.

• Faster runtime.: Rust's runtime performance is typically faster than Go's. CPU-intensive tasks benefit; the throughput is higher; the latency is lower.
• Safer.: Rust's borrow checker prevents many memory safety bugs at compile time. Concurrent code is more reliable; the discipline catches bugs early.
• Best for tools that need maximum performance.: When the CLI's runtime performance matters significantly, Rust is worth the additional complexity.
• Maximum performance.: Tools processing large amounts of data, network-intensive tools, performance-sensitive workloads benefit from Rust's runtime.
• Steeper learning curve.: The borrow checker takes time to internalize. New Rust engineers spend more time on the language; the productivity penalty is real but bounded.

Rust is the right choice for performance-critical CLI tools. The complexity is justified by the runtime benefits.

Decide

The decision depends on the tool's requirements. Go for daily use and ops tools; Rust for hot paths and performance-critical work.

• Go for daily use.: Most CLI tools are daily-use tools. Go's productivity advantages outweigh Rust's runtime advantages for these tools; Go is the right choice.
• Rust for hot paths.: When the tool's hot path matters, Rust's runtime advantage justifies the complexity. Performance-critical processing benefits.
• Most CLI tools are Go-suited.: The fast iteration, simple deployment, broad ecosystem all favor Go for typical CLI work. The team's default should be Go.
• Test before committing.: Before standardizing on a language, the team tests with their actual workload. The relative ease and performance guide the decision.
• Mixed-language is fine.: The team can use both. Go for most tools; Rust for specific performance-sensitive ones; the choice is per-tool.

Go vs Rust CLI is one of those tooling choices that benefits from clear thinking about requirements. Nova AI Ops integrates with development tooling, surfaces patterns, and supports the team's language choices.