I usually ask about the developer's experience and create scenarios based on what they consider their strengths. This approach is fairer, in my opinion, since not everyone has worked with AWS and S3, despite their common usage. Another important point is that you can never truly gauge how well a developer will fit until they actually start working for you. Given the current market is quite favorable for employers, and if you have the scope for development, it might make sense to start with several developers and then keep the one who fits best. However, in this case, please ensure you mention that there will be a probation period.
Additionally, I know many great developers who do not have portfolio websites.
Additionally, I know many great developers who do not have portfolio websites.