My tips on this: design it well, use proper patterns and threading. Make a GUI. Create a portable project (they use Eclipse) they can just run. I had pluggable algorithms, added new patterns and new data sets (which could be hot loaded into the app). Don't focus on the algorithm to the detriment of your design and documentation. I added Help section and wrote up a fairly detailed document. Note on the project, after I submitted it I never heard another word about it. I was prepared to discuss my design, ramifications of my decisions, how I would improve it etc, etc. Seemed like an opportunity lost to determine my "real world" skills.