• Tokenisation: the cost surface of LLMs

    Lesson 01 — the cost surface of LLMs. A practical first look at what every other lesson on this site will assume you’ve felt for yourself. Estimating LLM cost from word count can be off by a factor of two You’re sitting across from the head of a Maltese SME. They want to deploy an…

  • Forward pass: what actually happens when an LLM emits one token

    Lesson 02 — what actually happens when a model emits one token. After this lesson you should be able to narrate the forward pass without hand-waving. One token. Seven steps. Every token a large language model produces comes from the same seven-stage pipeline. Skip any one of them and you lose the ability to reason…

  • Sampling: temperature, top-k, top-p

    Lesson 03 — the difference between “the model said it” and “the model could have said it”. Sampling is where probability becomes language. Temperature, top-k, and top-p turn logits into a chosen token After the last block of the transformer, the model produces a vector of logits — one real number per token in the…

  • KV cache: the serving bottleneck

    Lesson 04 — the single most operationally important fact about LLM serving. Most teams discover this the expensive way. Caching K and V trades O(N²) recomputation for memory To generate token N, self-attention has to read the keys and values of every previous token. Token N+1 needs the same plus one more. Without caching, position…