Phi-4 Fine-Tuning on the U.S. Constitution
Fine-tuned a 14B LLM on a full legal text to produce a reference-backed legal QA assistant, with measured before/after performance gains.

Workflow & Architecture
How this system works
U.S. Constitution structured into instruction–response pairs for domain tuning.
Phi-4 trained with LoRA/QLoRA via Unsloth on legal QA and summarization tasks.
Before/after evaluation on 99 test queries for depth and citation accuracy.
FastAPI serves the fine-tuned model to the React chat interface.
Responses include explicit references to source constitutional text.
Overview
Used Unsloth (LoRA/QLoRA) to fine-tune Phi-4 on instruction–response pairs built from the U.S. Constitution, with a FastAPI backend and React frontend powering a chat interface with explicit source citations.
The Problem
Demonstrate that domain fine-tuning measurably improves an LLM's depth and accuracy on a specialized text, versus using it out of the box.
The Solution
Fine-tuned Phi-4 on structured Constitution-based instruction-response pairs with before/after benchmarking, reference-backed answers, and a production chat interface.
Key Features
- Structured instruction-tuning data built from raw legal text
- Before/after benchmarking of the fine-tuned model
- Reference-backed answers with explicit citations to source text
- QA, summarization, and amendment interpretation tasks
- FastAPI backend with React chat frontend
Outcomes & Business Value
- Average response length improved 32→47 words after fine-tuning
- Explicit source references improved from 45 to 78 out of 99 test queries
- Measurable, benchmarked gain from domain-specific LLM fine-tuning


