Transformer Architecture in 2026: From Attention to Mixture of Experts (MoE)

In 2026, the AI landscape is no longer just about "Attention Is All You Need" While the Transformer remains the foundational bedrock for every frontier model - from Claude, GPT-4o to Gemini 1.5 Pro the architecture has evolved into a sophisticated engine optimized for scale, speed, and massive context windows. If you are an AI engineer today, understanding the "classic" Transformer is the entry fee. To excel, you need to understand how Mixture of Experts (MoE), Sparse Attention, and State Space Models (SSMs) are reshaping the field.