SN was an early, Lisp-based deep learning simulator developed by Léon Bottou and Yann LeCun in 1988. Working with this historical software was highly labor-intensive, often requiring months of engineering effort involving C++ and assembly code to implement and optimize neural network models. This contrasts sharply with the rapid prototyping enabled by modern deep learning frameworks, which have streamlined what used to be a monumental engineering challenge into a process that takes only minutes.