It depends if you are looking for a developer, or designer. If it were a designer, I'd want to see examples of what they have done in the past.

If I was interviewing someone for a Service Portal developer position, ask them questions like:

• Give me an example of a time you implemented a live list using recordWatch
• Tell me about a challenging widget you built
• What do you consider the best feature of Service Portal and why?
• Give me an example of a widget you've built that uses templates?
• • Why did you choose templates for that use case instead of inline HTML?
• Tell me about a time you had to make two widgets communicate with each other.
• • What method did yo use and why?