I've interviewed at Amazon a few times. Ever since they implemented their coding challenge, it's made the entire process pointless. Before, technical interviews were conducted with an Amazon developer, and they could ask questions while you were writing out code. They could see how you approached problems and how you broke down complexity.

Basically, it was an evaluation of your skills as an engineer.

Now, the coding challenge is really more a test of your typing skills, the performance of the site's compiler, etc. It's a task that could easily be done by copy-pasting from some other site, but that's against the rules. It just gives you an entirely alien coding experience that doesn't actually measure anything that would indicate your quality as an engineer.

Create an algorithm that performs string manipulation.