Tell me about a clever solution of yours that backfired or caused new problems. What did the cleverness cost, and what did you do next?

Novelty has a known failure mode — complexity, fragility, surprise for everyone downstream — and candidates who innovate for real have met it. The question rewards an honest post-mortem over polish, and the what-next clause shows whether they cleaned up or moved on and left the mess.

• What warning signs did you miss — or dismiss?
• Who was hit by the side effects, and how did they find out?
• What did unwinding it involve?
• What do you check now before trying something clever?

A real backfire with named damage, ownership of the miss without theatrical self-flagellation, a cleanup they led rather than left to others, and a concrete check that now runs before their clever ideas ship.

The failure offered is a success in costume, the side effects were quietly absorbed by someone else, blame lands on the people who "didn't get it", or nothing has changed in how they vet ideas since.