What is fine-tuning an LLM?
PICTURE THIS: DATA SPLIT
Fit on train, tune on val, report on test once.
Simple meaning
Fine-tuning continues training on your examples so weights change.
WHY — Tokens instead of words?
LLMs use tokens (not full words) because it helps them:
separate people who only read docs from people who shipped.
and tied to GenAI / LLM work.
Each piece maps to a number the network can learn.
Fixed pieces are what transformers expect as input.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1Fine-tuning continues training on
your examples so weights change.
- 2It can teach format,
tone, and domain phrasing.
- 3It does not automatically
stay current unless you keep retraining on new facts.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
Fine-tuning continues training on your examples so weights change. It can teach format, tone, and domain phrasing.