Being able to use algorithms and data structures, which what this article mostly talks about, is rather a different thing from knowing how to implement them, which is what interviews go after.
That said, the only algorithm that I'm convinced that every single programmer needs to know by heart is state machines. Because using them can often save you a lot of code and complexity. And because you really have to know them well to recognize spots where they would be useful. And because using an off-the-shelf library to implement them is, for most use cases, more complicated, more time-consuming to implement, and less readable than a little light hard-coding.
That said, the only algorithm that I'm convinced that every single programmer needs to know by heart is state machines. Because using them can often save you a lot of code and complexity. And because you really have to know them well to recognize spots where they would be useful. And because using an off-the-shelf library to implement them is, for most use cases, more complicated, more time-consuming to implement, and less readable than a little light hard-coding.