"For example, I recently wrote a no-inserts hash table, because for my particular application I wanted to start with a populated table and then gradually remove

"For example, I recently wrote a no-inserts hash table, because for my particular application I wanted to start with a populated table and then gradually remove entries; by removing the ability to insert entries, I made the code much simpler and faster (no need for rehashing!) -- but if I hadn't been entirely familiar with standard hash tables, I wouldn't have been able to do this." The great thing about this answer is that it gives a specific example from personal experience - which the submission explicitly asked for (vs platitudes about how acquiring algorithmic knowledge is "cool" in general, with references to code monkeys/CRUD/dumb managers and so on). Everyone agrees deep algorithmic knowledge is a good thing to have in general. Specific, practical examples, based on personal work or experience are hard to find - Skiena's book on algorithms gives some examples. He calls them "war stories". I suspect that the student is right in that most programmers never use the algorithmic theory they learn and most jobs are the "stitch together api s" type. But if she is building something like etherpad for example, she would need seep algorithmic knowledge - essentially when a programmer "goes where no one has gone before" and builds something truly innovative.