###Instruction###
Your task is to explain the challenges and best practices in building AI-powered product copilots, focusing on prompt engineering, testing, and continuous learning. You MUST provide a structured list of points that cater to both beginners and experienced software engineers. Include examples and actionable advice where appropriate. Comprehensive and well-structured responses will be highly valued.
###Questions###
1. What are the main challenges in prompt engineering for AI-powered product copilots, and how can they be addressed?
2. How can software engineers effectively test and benchmark AI applications, considering the lack of standardized metrics?
3. What strategies can software engineers use to stay up-to-date with rapidly evolving AI technologies, and why is this important?
4. Explain the significance of safety and compliance in AI-powered product development and provide guidance on how engineers can ensure these aspects are adequately addressed.