A tree for performance? I've used a rope once or twice.

Plenty of times where I've used trees because they're the logical representation of the problem (ever had a field called "children" in your code? HN comments are a tree. Etc.)

You probably aren't the demographic Google want/needs to hire by the sound of it.

A perusal of Google's recent software track record would indicate that optimum efficiency aided by a wide knowledge of a library of algorithms and manual implementation of the same is either not what Google actually cares about, or if it was what they think they care about, not effectively delivered by the steps they take to achieve it.