Top 3 Kill switch Interview Questions

Browse 3 real-world technical and behavioral interview questions about Kill switch. Review scenarios, edge cases, and architectural best practices.

An upstream feed resets ten thousand of your prices to a penny and orders start arriving. What should have stopped it, and what do you do with the orders that got through?

Nothing in the pricing engine was broken, so the control has to sit on the change itself: bounds relative to the previous price and the cost, a rate limit on bulk movement, and a kill switch. Then pause dispatch before anyone debates whether to honour the orders.

hardscenario

A configuration change that passed review takes the entire fleet down in under a minute. What in your design should have limited the damage?

No retry policy or circuit breaker helps here, because the change was valid and the defect was already deployed. What bounds the damage is treating configuration as a rollout with stages and bake time, a kill switch whose own dependencies cannot fail with it, and a measured rollback time.

hardscenario

How would you put mandatory pre-trade risk checks on the order path when the desk will not accept the latency?

Pre-trade risk checks must stay on the order path without adding unacceptable latency. Keep static checks in-process, maintain bounded counters for local exposure and grant budgets for global limits, with a kill switch that fails safe. It also connects market access to the point an interviewer is testing.

harddesign