Walk me through the lifecycle of an equity order from the click to settlement.

Short answer

An equity order is validated and risk-checked at the broker, routed to a venue, matched by price-time priority into one or more fills reported back as execution reports, allocated to end accounts, novated to a clearing house that becomes the counterparty, and finally settled against cash at the custodian on T+1.

Keep order lifecycle explicit in the answer because that is the concept the interviewer is actually trying to test. A good order lifecycle explanation names the trade-off, the failure mode, and the evidence you would use before choosing. Use order lifecycle once more at the decision point so the answer reads as judgement rather than a detached example.

Keep order lifecycle explicit in the answer because that is the concept the interviewer is actually trying to test.