Walk through methodically: "Transaction enters mempool, validator orders by priority fee, EVM executes opcodes consuming gas, state is applied atomically on success or fully reverted on failure, block is finalised by consensus."
Transaction lifecycle: user signs transaction, broadcasts to mempool, validator/miner selects and includes in block, EVM executes bytecode in a sandboxed environment (stack-based, 256-bit words), state changes are applied if execution succeeds (or reverted on failure), gas is consumed per opcode, block is proposed and finalised by consensus. Strong candidates discuss: gas estimation, nonce management, EIP-1559 fee mechanism, and the difference between transaction execution and block finality.
Foundational EVM knowledge. Candidates who cannot explain execution at this level will struggle to debug on-chain issues or optimise gas. Ask what happens when a transaction runs out of gas mid-execution.