What Prompt Engineers Actually Do
Prompt engineering has matured beyond "write clever prompts." Production prompt engineering involves systematic processes.
Prompt Design & Optimization
Core prompt crafting work:
- System prompts — Defining model behavior, tone, and constraints
- Few-shot examples — Curating demonstrations that guide outputs
- Chain-of-thought — Structuring reasoning to improve accuracy
- Output formatting — Ensuring structured, parseable responses
- Edge case handling — Addressing failure modes and unexpected inputs
Evaluation & Testing
Rigorous output assessment:
- Evaluation frameworks — Building systems to measure prompt quality
- Test suites — Creating comprehensive test cases
- A/B testing — Comparing prompt variants systematically
- Regression testing — Ensuring prompt changes don't break existing behavior
- Human evaluation — Coordinating human assessments for subjective quality
Production Systems
Engineering work around prompts:
- Prompt management — Versioning, deployment, rollback systems
- Context management — Handling conversation history, context windows
- Cost optimization — Reducing token usage while maintaining quality
- Latency optimization — Balancing response time with output quality
- Monitoring — Tracking prompt performance in production
Domain Expertise
Specialized prompt work:
- RAG systems — Retrieval-augmented generation prompt design
- Agent systems — Prompts for tool use, planning, and reasoning
- Fine-tuning data — Creating training data informed by prompt insights
- Safety & alignment — Preventing harmful outputs, jailbreaking
Skills by Experience Level
Junior Prompt Engineer (0-1 years)
Capabilities:
- Write clear, effective prompts for single tasks
- Understand basic prompt patterns (few-shot, chain-of-thought)
- Test prompts manually and identify issues
- Document prompt behavior and limitations
- Work with one or two LLM providers
Learning areas:
- Systematic evaluation methods
- Production prompt management
- Cost and latency optimization
- Advanced prompting techniques
Mid-Level Prompt Engineer (1-3 years)
Capabilities:
- Design prompt systems for complex workflows
- Build evaluation frameworks and metrics
- Optimize for cost, latency, and quality
- Work across multiple LLM providers
- Identify and mitigate failure modes
- Collaborate with ML and software engineers
Growing toward:
- Architecture decisions for AI systems
- Team leadership
- Strategic prompt system design
Senior Prompt Engineer (3+ years)
Capabilities:
- Architect production AI systems
- Define evaluation strategies and quality bars
- Make build vs. buy decisions for AI infrastructure
- Lead teams on prompt strategy
- Stay current with rapidly evolving best practices
- Bridge business requirements and technical implementation
Curiosity & fundamentals
Independence & ownership
Architecture & leadership
Strategy & org impact
Interview Focus Areas
Prompt Design Skills
Evaluate practical prompt crafting:
- Live exercise — Give a task and have them design a prompt
- Debugging — Show a failing prompt and ask them to diagnose it
- Optimization — Present a working but suboptimal prompt for improvement
- Edge cases — Ask how they'd handle specific failure modes
Evaluation Mindset
Critical thinking about outputs:
- "How would you measure if a prompt is working well?"
- "What metrics would you use for [specific use case]?"
- "How do you handle subjective quality assessment?"
- "How do you balance automated vs. human evaluation?"
Technical Understanding
LLM knowledge depth:
- "Explain how temperature affects outputs"
- "What's the difference between zero-shot and few-shot prompting?"
- "How do context windows affect prompt design?"
- "What causes hallucinations and how do you mitigate them?"
Production Awareness
Systems thinking:
- "How would you version and deploy prompts?"
- "How do you handle prompt changes without breaking production?"
- "What's your approach to cost optimization?"
- "How do you monitor prompt performance?"
Common Hiring Mistakes
Hiring Based on ChatGPT Experience
Using ChatGPT doesn't make someone a prompt engineer. Look for:
- Systematic approach, not trial-and-error
- Understanding of WHY prompts work
- Production experience, not just playground exploration
- Evaluation and testing rigor
Undervaluing Engineering Skills
Pure prompt design pays less and limits scope. For production systems, you need:
- Software engineering fundamentals
- API integration experience
- Understanding of system design
- Ability to build tooling
Expecting Stable Best Practices
The field evolves monthly. New models, new techniques, new capabilities. Hire for:
- Learning ability and curiosity
- Empirical rigor (testing, not assuming)
- Adaptability as techniques change
- Community engagement
Ignoring Domain Knowledge
Prompt engineering for customer service differs from coding assistants differs from medical applications. Domain expertise helps:
- Understanding use case nuances
- Designing appropriate evaluation criteria
- Anticipating edge cases
- Communicating with stakeholders
Where to Find Prompt Engineers
High-Signal Sources
- AI communities — Anthropic Discord, OpenAI forums, LangChain community
- Technical content — Writers about prompt engineering, LLM systems
- GitHub — Contributors to prompt libraries, LLM frameworks
- ML adjacent — Data scientists, NLP engineers transitioning
- daily.dev — AI-focused developers discussing LLM patterns
Background Considerations
| Background | Strengths | Gaps |
|---|---|---|
| ML Engineers | Model understanding, evaluation | May over-engineer |
| Technical Writers | Clear communication, instruction design | May lack engineering skills |
| Software Engineers | Systems thinking, production skills | May need LLM-specific learning |
| Linguists | Language understanding | May need technical skills |
Recruiter's Cheat Sheet
Resume Green Flags
- Production LLM system experience
- Evaluation framework development
- Experience with multiple LLM providers
- Background in NLP, ML, or linguistics
- Technical writing or instruction design
- Software engineering skills alongside prompt work
Resume Yellow Flags
- Only ChatGPT or playground experience
- No systematic evaluation approach
- Purely creative/writing background without technical skills
- Claims of "prompt engineering" that are actually just using AI tools
Technical Terms to Know
| Term | What It Means |
|---|---|
| Few-shot learning | Including examples in the prompt |
| Chain-of-thought | Prompting for step-by-step reasoning |
| System prompt | Instructions defining model behavior |
| Temperature | Randomness control parameter |
| Context window | Maximum input size for the model |
| Hallucination | Model generating false information |
| RAG | Retrieval-Augmented Generation |
| Token | Unit of text (roughly 4 characters) |
| Fine-tuning | Training model on custom data |
| Embedding | Vector representation of text |