How the first learning machine worked: an artificial neuron, the perceptron rule, the XOR limit, and the layers that solved it.
A whiteboard session: the RAG pipeline built stroke by stroke, offline preparation and online query handling, then the same system as a funnel from ten thousand chunks to one answer.
A whiteboard session: one small network drawn once and annotated twice, black forward to a prediction, red backward to hand out the blame, then every weight updated by hand.