Just this morning on the train I read "On the Criteria To Be Used in Decomposing Systems into Modules" by D.L. Parnas (1972). And then on the same day I get Bar

Just this morning on the train I read "On the Criteria To Be Used in Decomposing Systems into Modules" by D.L. Parnas (1972). And then on the same day I get Barbara Liskov telling me how it was back in those days figuring all of this out! I much enjoyed the tour of how these foundations came together. The funniest part was where she classifies the Liskov-Principle as just that intuitive rule meant to help the OO people which were confused about type hierarchy. The hard things don't seem so hard once you've understood them.