> The flip side is the candidate that memorized the book, prepared like it's a test at school, and is useless on the job, can't operate at all outside that memo

> The flip side is the candidate that memorized the book, prepared like it's a test at school, and is useless on the job, can't operate at all outside that memorized domain, can't write the simplest bit of real world code. I think this leaves out the possibility of high mastery. I think it is instructive think about algorithm skills as similar to those for algebra. If the most advanced algebra you ever solved was linear equations, remembering how to solve a linear equation may be difficult. However if you're skilled at solving advanced calculus problems by hand, your understanding of algebra is so deep that you could re-derive the process as necessary. Many of us with a lot of math experience will never forget how to solve linear or quadratic equations barring steep cognitive decline and this is also so true for certain classes of algorithms. Personally, I've studied graphs and graph algorithms beyond what you might find in just CLRS or other introductory algorithms textbooks and as a result I can re-derive many classic graph algorithms on the fly, no memorization necessary. I have done this interviews as have people I know.