Give us an example of a difficult technical problem you had to solve. What was the problem and how did you resolve it?
This is an opportunity to tell your story and for you to demonstrate not just what you do but how well you do it. Taking the interviewer through one or more of your problem solving achievements can be a powerful and compelling message to the interviewer who's listening. Your problem solving abilities will be uniquely yours so answer with as much pride and positive energy as possible. Offer an overview of the challenge, the actions you took and the successful results. In addition to the actual information involved, look at it as a way for your interviewer to get to know you better and how you make good things happen. A well-prepared and well-thought-through answer here can easily take you to the next level.