Choose Rust for high-performance, memory-safe systems where concurrency is critical, or Kotlin for rapid development on the JVM with strong Android integration. Rust compiles to native code with zero-cost abstractions, while Kotlin leverages the JVM ecosystem and garbage collection. For a new backend service requiring maximum throughput and low latency, use Rust; for a team already invested in Java or needing quick iteration, use Kotlin.
// Rust: Native, zero-cost concurrency
#[tokio::main]
async fn main() {
println!("Rust backend running");
}
// Kotlin: JVM-based, rapid development
fun main() {
println("Kotlin backend running")
}