1. Multi-Head Attention Residual Add + LayerNorm
Projects input tokens into multiple subspaces, allowing simultaneous tracking of syntax, coreference, and positional context.
Why this matters: Enables parallel token interaction without sequential recurrent bottlenecks (O(1) sequential path length).
2. Feed-Forward Network (FFN) d_model → 4×d_model → d_model
Two linear transformations with a non-linear activation (GELU/ReLU) applied identically to each token position.
Why this matters: Stores factual knowledge keys and expands dimensionality to synthesize gathered contextual cues.
3. Residual Skip Connections & LayerNorm x + SubLayer(LayerNorm(x))
Preserves gradient highways across dozens of stacked layers preventing vanishing gradients.