A working implementation is only one part of a smart contract engineering assessment. Hiring teams also need to understand how a candidate reasons about assumptions, failure and review. Build the interview around the actual contract environment rather than a generic blockchain knowledge test.
Define the domain before the assessment
State the execution environment, the types of contracts and the expected ownership. A developer implementing application logic and an engineer designing protocol mechanisms may need different depth. Explain whether the role includes incident response, upgrade planning or coordination with external reviewers.
Keep domain requirements distinct from language familiarity. A candidate can know the syntax well while having limited experience with the risks relevant to your system. Equally, experience in one environment does not automatically transfer to every other one.
Start with a trust-boundary discussion
Present a simplified design and ask what the candidate needs to know before implementing it. Which inputs are untrusted? Which actors have privileged actions? What external components or services does the design depend on? What assumptions would need to hold for the intended behaviour to remain safe?
Allow the candidate to identify missing information. A thoughtful request for context is useful evidence, not a failure to solve the task immediately. Ask them to prioritise the assumptions they would investigate first.
Ask what they would test
Move from normal behaviour to invariants and unexpected sequences of actions. What should always remain true? Which edge cases deserve attention? How would they review the relationship between the stated requirements and the implementation?
Use a small, purpose-built example. Do not ask candidates to audit live production code as an unpaid interview assignment, and do not treat a successful interview exercise as a security assurance for your system.
Explore review and release behaviour
Ask about a change the candidate has taken through review. How did they communicate the design, respond to a concern and decide whether the change was ready? Where did they rely on specialist help?
Then discuss a hypothetical issue discovered late in the process. Look for a reasoned response that considers impact, evidence and communication rather than a rush to defend the implementation. A candidate who recognises the limits of their knowledge can be more useful than one who claims every risk is solved.
For EVM/Solidity contexts, OWASP’s Smart Contract Security Verification Standard provides a reference for security requirements. Use relevant material to inform discussion; it is not a ready-made hiring test or a substitute for independent security review.