Prompt Engineer, Agent Prompts & Evals

About the Role

We’re looking for prompt and context engineers to join our product engineering team to help build AI-first products, features, and evaluations. Your mission will be to bridge the gap between model capabilities and real product experience, working with product teams to build consistent, safe, and beneficial user experiences across all product surfaces.

You will be deeply involved in new product feature and model releases at Anthropic, combining engineering expertise with an understanding of frontier AI applications and model quality. You’ll become an expert on Claude’s behavioral quirks and capabilities and apply that knowledge to deliver the best possible user experience across models and domains. You’ll be the first resource for product teams working on Claude’s AI infrastructure: system prompts, tool prompts, skills, and evaluations.

This role requires someone who can effectively balance caring deeply about making Claude the best it can be while also supporting a wide variety of concurrent projects and efforts across many product teams.

Key Responsibilities

• Prompt Engineering Excellence: Design, test, and optimize system prompts and feature-specific prompts that shape Claude’s behavior across consumer and API products.
• Evaluation Development: Build and maintain comprehensive evaluation suites that ensure model quality and consistency across product launches and updates.
• Cross-functional Collaboration: Partner closely with product teams, research teams, and safeguards to ensure new features meet quality and safety standards.
• Model Launch Support: Play a critical role in model releases, ensuring smooth rollouts and catching regressions before they impact users.
• Infrastructure Contribution: Help build and improve the frameworks and tools that allow teams to develop and test prompts and features with confidence.
• Knowledge Transfer: Mentor product engineers on prompt engineering best practices and help teams build their first evaluations.
• Rapid Iteration: Work in a fast-paced environment where model capabilities advance daily, requiring quick adaptation and creative problem-solving.

What We’re Looking For

Required Qualifications

• 5+ years of software engineering experience with Python or similar languages.
• Demonstrated experience with LLMs and prompt engineering (through work, research, or significant personal projects).
• Strong understanding of evaluation methodologies and metrics for AI systems.
• Excellent written and verbal communication skills – you’ll need to explain complex model behaviors to diverse stakeholders.
• Ability to manage multiple concurrent projects and prioritize effectively.
• Experience with version control, CI/CD, and modern software development practices.

Preferred Qualifications

• Experience with Claude or other frontier AI models in production settings.
• Background in machine learning, NLP, or related fields.
• Experience with A/B testing and experimentation frameworks (e.g., Statsig).
• Familiarity with AI safety and alignment considerations.
• Experience building tools and infrastructure for ML/AI workflows.
• Track record of improving AI system performance through systematic evaluation and iteration.

You Might Thrive in This Role If You…

• Get excited about the nuances of how language models behave and love finding creative ways to improve their outputs.
• Enjoy being at the intersection o