Leaning Into the Coding Interview: Lean 4 vs Dafny cage-match
Summary
This blog post compares Lean 4 and Dafny in the context of coding interviews and formal verification, illustrating how Lean functions as both a programming language and a proof assistant. It walks through practical examples (like fizzbuzz) and demonstrates tactics, proof strategies, and the tradeoffs between Lean's interactive proofs and Dafny's automatic proving, highlighting the role of dependent types and the human effort involved in formal verification.