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What is Prompt Engineering?

Learn what prompt engineering means. Understand techniques for crafting effective prompts and why monitoring prompt performance matters.

By DriftRail · Updated

Prompt engineering is the practice of designing and optimizing inputs to LLMs to get better outputs. This includes crafting system prompts, using few-shot examples, structuring queries, and iterating based on results.

Key Techniques

  • System prompts: Set context and behavior
  • Few-shot: Provide examples of desired output
  • Chain-of-thought: Request step-by-step reasoning
  • Structured output: Request JSON or specific formats

Prompt Engineering for Safety

  • Include safety instructions in system prompts
  • Request citations and sources
  • Ask model to express uncertainty
  • Define boundaries and refusals

Measuring Prompt Performance

  • Track hallucination rates by prompt version
  • A/B test prompt changes
  • Monitor quality metrics over time
  • Compare prompts across different models

How do I know if prompts work?

Monitor prompt performance in production. Track hallucination rates, user satisfaction, and task completion by prompt version. A/B test prompt changes and measure impact on quality metrics.

Practical example

A prompt is revised to require an answer grounded in supplied policy passages and to escalate missing evidence.

What to check

Compare the change on a held-out task set with the same model, retrieval data, and scoring rubric.

Limits and tradeoffs

A better prompt cannot replace permissions, reliable source data, or application-side enforcement.

Maintained by DriftRail. AI assisted the October 2026 content and template revision. Examples are illustrative; they are not measured product benchmarks. Suggest a correction.

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