Sorry for off-topic. Several years ago I watched part of a video lecture about implementing Excel principles. It was a talk about functional programming, and he

Sorry for off-topic. Several years ago I watched part of a video lecture about implementing Excel principles. It was a talk about functional programming, and he may have used Haskell, or Scala. I found it interesting because it began with him explaining how Excel is huge array and how changes propagate. Do you have a link to this talk/lecture? Thanks in advance!