I recently had a need for an algorithm that did some pretty complex geographical data interpolation that was faster than the existing implementations. The modern vendor library I was using took about a minute to compute.
I searched through some old archives and found a scanned in PDF of the algorithm I wanted to implement from a late 60s fortran implementation. I converted it to node.js and Presto! The thing takes the exact same inputs, gives the exact same outputs, and does it all in... 35 milliseconds.
With the complexity of the algorithm and size of the dataset I am pretty sure it would have taken a mainframe the size of a warehouse and weeks to compute back then, but it showed me that the underlying data structures and mathematics have not changed in the least.
I have always tried to take it to heart that "we stand on the shoulders of giants" and all that, but this was really a turning point for me over the last few weeks, that many of the greats from the past would make us all look like morons if they were around today.
There are implementations of this algorithm in C, C++, Java, Python, Javascript, and probably others, but they are all at least an order of magnitude slower than the one that came out back then, given the same modern hardware, even in a language that is not exactly known for its computational prowess.