Chapter 5 ยท Section 2

The Compilation Concept

Transform high-level program specifications into optimized prompts and weights.

~10 min read

๐Ÿ”ง What is DSPy Compilation?

DSPy compilation transforms your high-level program into optimized prompts and weights. Unlike traditional compilation that converts source code to machine code, DSPy compilation optimizes the language model interactions within your program.

The compilation process includes:

โœ๏ธ

Automatic Prompt Engineering

Crafting optimal prompts for your specific task

๐Ÿ“‹

Example Selection

Choosing the best demonstrations for few-shot learning

โš™๏ธ

Weight Tuning

Optimizing module parameters for better performance

๐Ÿ”—

Pipeline Optimization

Improving the overall program structure

๐Ÿ”„ The Compilation Pipeline

import dspy
from dspy.teleprompt import BootstrapFewShot

# Before compilation: High-level specification
class QASystem(dspy.Module):
    def __init__(self):
        super().__init__()
        self.generate_answer = dspy.ChainOfThought("question -> answer")
    
    def forward(self, question):
        return self.generate_answer(question=question)

# Define metric
def answer_exact_match(example, pred, trace=None):
    return example.answer.lower() == pred.answer.lower()

# After compilation: Optimized prompts and weights
optimized_qa = BootstrapFewShot(metric=answer_exact_match).compile(
    QASystem(),
    trainset=train_data
)

โš™๏ธ How Compilation Works

1๏ธโƒฃ

Program Specification

You define the high-level structure using DSPy modules

2๏ธโƒฃ

Training Data

Provide examples of inputs and desired outputs

3๏ธโƒฃ

Optimization Metric

Define how to measure performance (accuracy, F1, etc.)

4๏ธโƒฃ

Compilation

DSPy automatically optimizes using the specified optimizer

5๏ธโƒฃ

Evaluation

Test the compiled program on held-out data

๐Ÿ“ฆ Types of Compilation

Prompt Compilation

Optimizes the natural language instructions:

  • Rewrites instructions for clarity
  • Adds relevant context
  • Formats examples optimally

Example Compilation

Selects and orders training examples:

  • Chooses diverse examples
  • Orders by difficulty or relevance
  • Balances different types of cases

Weight Compilation

Optimizes module parameters:

  • Adjusts confidence thresholds
  • Tunes generation parameters
  • Optimizes module interactions

๐Ÿ“Š Compilation vs Traditional Programming

Traditional Programming DSPy Compilation
Source code โ†’ Machine code High-level LM program โ†’ Optimized prompts
Static optimization Dynamic optimization based on data
One-time compilation Iterative improvement possible
Hardware-specific Task and data-specific
Manual optimization required Automatic optimization

๐ŸŽฏ When to Use Compilation

โœ…

Use compilation when:

  • You have training data available
  • Performance is critical
  • Task is complex or nuanced
  • You want consistent results
  • Manual prompt engineering is time-consuming
โš ๏ธ

Skip compilation when:

  • Task is very simple
  • No training data available
  • One-off tasks
  • Rapid prototyping needed

๐Ÿ’ก Compilation Best Practices

Start Simple

# Start with this
simple_classifier = dspy.Predict("text -> category")

# Then compile for better performance
optimized = BootstrapFewShot(metric=accuracy).compile(
    simple_classifier, 
    trainset=data
)

Use Sufficient Training Data

# Minimum 10-20 examples for basic tasks
# 50-100+ examples for complex tasks
# Diversity in examples is crucial

Choose the Right Metric

# For classification: accuracy, F1
# For generation: ROUGE, BLEU
# For QA: exact match, F1
# Custom metrics for domain-specific tasks

Validate Properly

# Split data properly
train_data, val_data = train_test_split(all_data, test_size=0.2)

# Compile on training data
compiled_program = optimizer.compile(program, trainset=train_data)

# Evaluate on validation data
results = evaluate(compiled_program, val_data)

๐Ÿ“ Key Takeaways

DSPy compilation automatically optimizes LM interactions

Transforms high-level programs into optimized prompts and parameters

Process is data-driven and reproducible

Different types: prompts, examples, and weights

Proper validation is essential for success