Top 50 Rust Interview Questions & Answers (2026)

01 What is Rust and what problems does it solve? 02 What are Rust's ownership rules? 03 What is borrowing in Rust? 04 What is the borrow checker in Rust? 05 What are lifetimes in Rust? 06 How do you define structs and impl blocks in Rust? 07 What are Rust enums and how do they differ from C enums? 08 What is the match expression in Rust? 09 What is Option<T> in Rust and why does Rust have no null? 10 What is Result<T, E> in Rust? 11 What is Cargo and what are its main commands? 12 What are closures in Rust? 13 What are traits in Rust? 14 What are iterators and the Iterator trait in Rust? 15 What is Vec<T> in Rust? 16 What is the difference between String and &str in Rust? 17 What are Rust modules and the use statement? 18 What are if let and while let in Rust? 19 What is pattern matching with destructuring in Rust? 20 What is a panic in Rust and when does it occur?

01 How does error handling with the ? operator work in Rust? 02 What are the thiserror and anyhow crates for error handling? 03 What are trait objects (dyn Trait) in Rust? 04 What are generics in Rust and how do where clauses work? 05 What are Rust smart pointers? 06 How does async/await work in Rust? 07 What is the Tokio runtime and how is it used in Rust? 08 What are Rust channels for message passing? 09 How do you use thread::spawn in Rust? 10 How does unit testing and integration testing work in Rust? 11 What is unsafe Rust and what does it allow? 12 What is the difference between procedural macros and declarative macros in Rust? 13 What are derive macros and which common ones does Rust provide? 14 What is Serde and how is it used in Rust? 15 What is Clap and how do you use it for CLI argument parsing? 16 What are lifetimes in structs and function signatures in Rust? 17 What are associated types vs generic parameters in Rust traits? 18 What is interior mutability in Rust? 19 What are Rust's concurrency primitives (Send and Sync traits)? 20 What is a HashMap in Rust and how is it used?

01 What are zero-cost abstractions and monomorphization in Rust? 02 What are Pin<T> and Unpin in Rust async programming? 03 How does the async runtime work internally in Rust (Waker, Poll, Executor)? 04 What are the rules for writing correct unsafe Rust? 05 How does Rust FFI (Foreign Function Interface) work with C? 06 What is procedural macro metaprogramming with syn, quote, and proc_macro2? 07 How do you implement a custom global allocator in Rust? 08 How do you compile Rust to WebAssembly? 09 What are Rust performance optimization techniques? 10 What are Rust editions and what changed across 2015, 2018, and 2021?