Describe the full pipeline: "Unit tests in Foundry for logic, fuzz tests for edge cases, Slither for static analysis, fork tests against mainnet, then external audit. Post-launch, we run a bug bounty on Immunefi."
Layered testing: unit tests (Foundry/Hardhat) for individual functions, integration tests for contract interactions, fuzz testing (Foundry fuzz or Echidna) for edge cases, formal verification for critical invariants, fork testing against mainnet state, and gas benchmarks. Pre-deployment: internal review, external audit for high-value contracts, bug bounty programme post-launch. Strong candidates mention Slither for static analysis and specific fuzzing strategies.
Tests professional practices. Smart contracts are immutable and handle real value — inadequate testing is unacceptable. Candidates who only write basic unit tests are not ready for production contracts. Ask about a bug their testing caught.