I recently started and finished two algorithm courses offered by Stanford on coursera. The courses were more challenging than I originally anticipated. Tracing through the logic of the code often requires you to be completely alert and focused, and it sometimes feels like a mind gymnastic class. Still, it was incredibly satisfying to see your code works, and runs fast! As a data scientist, I often write one-off analysis scripts that place little emphasis on computational performance. So naturally, I did not know what a difference does efficient code and suitable data structure makes until forcing myself to think like a software engineer.