As a software developer, it’s incredibly common to browse a codebase and find that the functionality that was advertised doesn’t really exist.
Maybe the function or class method is there, but where there should be some brilliant logic, instead there’s a comment to the effect of “TODO: actually implement this.”
It’s frustrating, especially if you know that the developer who wrote that comment is long-gone, but what can you do? The nature of the industry is that we’re hopping between projects (or jobs) almost constantly; how can anyone remember all of the “when I get time, I need to get back to that” demands on them?
