CPU for complex control flow, GPU for large-scale parallel computation, TPU for matrix operations pushed to the extreme. For most engineers, the real decision is cloud inference on GPU vs CPU, and when a TPU rental is worth it.
Recursive self-improvement (RSI) is one of the most discussed paths to AGI, but in reality AI self-improvement remains bounded by training data limits, evaluator reliability, and alignment problems. In 2026, AI can improve task-specific prompts and code, but there are clear technical barriers to 'true' RSI.
KV Cache reduces autoregressive Transformer generation from O(n²) — recomputing the full sequence for every new token — to O(n) per step, which is the core reason modern LLM inference is fast enough to be usable.
Transformer self-attention is inherently orderless — positional encoding is the fix. From sinusoidal absolute encoding, to learnable absolute encoding, to relative positional encoding, to RoPE (Rotary Position Embedding): modern LLMs almost universally use RoPE because it requires no parameters, naturally encodes relative distances, and can be extended to longer sequences.
LLM output quality is determined at three distinct layers: token-level decoding strategy, task-level workflow design, and model-level reasoning capability. Knowing which layer your problem lives in is the fastest path to fixing it.