The question was a long coding assignment in which the candidate is asked to develop a controller in MATLAB, for a simple vehicle point-mass model, that has it follow a straight line path and then executes a U-turn. The model is provided by the interviewers but then you have to put together a presentation for the panel regarding your findings and whatnot.
Sigiloso
There a few lateral controllers that can be utilized in this problem. A quick research on the web can land you a few. It is not a hard concept to learn but cumbersome to implement and get it running.