Brief #15 · AI & LLM

Fine-Tune a Tiny LLM

Hard⏱ 20-28 hSoon

Fine-tune a small open model on your own support tickets with LoRA, and prove with an eval set whether it actually beats good prompting.

Outlines are free · building with tracking needs Pro

FThe briefFrom the team

We pay a large model to sort and draft replies for 40,000 support tickets a month, and the bill keeps growing. Someone suggested fine-tuning a small model we can run ourselves. Before we commit, find out honestly: is a tuned small model as good as the big one with a good prompt, how much cheaper is it, and where does it fail?

What you'll build

  1. 1Build a labelled dataset of 2,000 tickets (category plus a good reply), and split it into train, validation and a held-out test set nobody touches until the end.
  2. 2Measure two baselines on the test set first: the big model with a careful prompt, and the small model with the same prompt.
  3. 3Fine-tune the small model with LoRA, tracking training and validation loss, and stop before it overfits.
  4. 4Score all three on accuracy for the category and a rubric-based judge for replies, and look at 30 failures by hand.
  5. 5Serve the tuned model behind an API and measure latency and cost per 1,000 tickets against the big model.

Step-by-step walkthrough

Walkthrough coming soon

This project's step-by-step walkthrough, with real outputs at every step, is still being written. You can read the brief and try it on your own meanwhile; tracking opens when the walkthrough is ready.

Done when

  • A results table: accuracy, reply score, latency and cost for all three, on the same held-out test set.
  • Training and validation loss curves, and the point where you stopped and why.
  • A written recommendation: switch, don't switch, or switch only for some ticket types.
  • No test-set ticket was ever used for training or prompt tuning.

Stretch goals

  • Quantize the tuned model to 4-bit and measure what it costs in quality.
  • Mix Bangla and English tickets and check whether quality holds for both.

Show it off