If you've built ZK circuits with Circom before, you already have a head start with Midnight's Compact language. The core instinct is the same: express computation in a way a prover can prove and a verifier can verify, without leaking private data. What changes is the shape of that instinct — Compact is a full contract language, not a circuit DSL, and that difference runs deeper than syntax. This isn't a beginner's intro to zero-knowledge proofs. It's a translation guide for someone who already thinks in signals and templates and wants to understand what those map to when writing Compact contracts on Midnight. The areas that trip people up most: concept mapping, the ledger (nothing like it exists in Circom), and a handful of pitfalls that catch almost everyone on the transition. Different problem, similar intuition Circom does one thing: describe a constraint system.…