I have recently passed several technical interviews at multiple large companies. The first one I botched completely. Then I looked at some algorithmic courses from Princeton on Coursera and passed the rest of the interviews in a breeze.
My point is, there _are_ free and good quality courses out there and if you have enough experience with actual work then it is just a matter of brushing up on the foundation. In the end I’m glad that I did.
Well, yes. However if you are already a good programmer then it will not take that much time, and if you are looking for a job then there is nothing wrong in expecting that you would prepare. And I would argue that it's not sunk time either. In my day to day job I do not use that many algorithms because most of the actually needed ones are hidden by the internals of the language, I got rusty and the refresher was useful.
My point is, there _are_ free and good quality courses out there and if you have enough experience with actual work then it is just a matter of brushing up on the foundation. In the end I’m glad that I did.