Engineering2026-09-172 min read

fine-tuning

VDaily Team
Maintainer

Fine-Tuning Guide — Agentic Design

Overview#

Plan, train, evaluate, and operate model adaptations with explicit trade-offs and safeguards.

What Fine-Tuning Changes#

Fine-tuning updates some or all of a pretrained model's parameters using task examples or preference feedback. It can improve measured behavior (output structure, tone, task accuracy) but does not automatically add fresh knowledge, eliminate hallucinations, or make a model safe.

Good Reasons to Test Fine-Tuning#

  • A stable, repeated behavior resists prompt-only fixes
  • You have representative examples and a trustworthy evaluation set
  • Shorter prompts or a smaller model may improve serving economics
  • The chosen checkpoint and artifacts can be deployed and governed

Reasons to Use Another Approach#

  • Use retrieval or tools for changing or attributable knowledge
  • Improve prompts when the desired behavior fits clear instructions
  • Fix the product or data pipeline when the model lacks required context
  • Delay training when data rights, quality, or evaluation are unresolved

Release-Oriented Workflow#

  1. Write the product goal, acceptance rubric, and failure budget
  2. Create a sealed holdout from production-shaped cases
  3. Measure prompt-only, few-shot, retrieval, and tool-use baselines
  4. Select a licensed base model and smallest practical adaptation method
  5. Run a short, reproducible pilot and inspect learning curves
  6. Compare quality, regressions, latency, throughput, and total serving cost
  7. Canary the winning candidate with monitoring and tested rollback

Minimum Comparison Report#

  • Base checkpoint, prompt, retrieval, and tuned candidate on same holdout
  • Per-slice task results with sample counts
  • Safety and base-capability regressions with release thresholds
  • Training configuration, seed, code revision, data revision, artifact hashes
  • Measured latency, throughput, memory, and cost on serving stack
  • Named owner, canary plan, monitoring signals, rollback procedure
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fine-tuning — Blog — VDaily