It can be if they give you something to start with. One company gave out sample code and asked me to optimize it so it ran under 5 seconds. The exercise was in

It can be if they give you something to start with. One company gave out sample code and asked me to optimize it so it ran under 5 seconds. The exercise was in parallelizing or caching/reusing what you could per the requirements. it was great because: - problem statement clearly defined - skeleton code provided - about 2 hours to complete - solved an actual, real-world problem