The original question
“What portfolio format do you recommend (web or PDF)? ”
It depends on the audience so be empathic
A portfolio is made to convince a particular audience, so think about what that audience needs. And there are different people who will go through your portfolio:
The person who does the first sorting: this can be a secretary, an HR person who might not know much about Service Design and not be into all the fancy interactive digital stuff.
The people who will work with you: these are the people who will take the time to go really into the details of your portfolio, they will study every detail. These are the people who might like some fancy interactive stuff.
The decision maker: the final person who needs to validate the hire and who will recieve a recommendation from other colleagues. This person often doesn't have much time.
Depending on the side of the organization you want to work at, these profiles might be in different people, or it might be just all the same person.
My two cents
In my own experience both as someone who has to hire or wants to get hired I feel a good slide deck (which can be interactive) but also available in PDF format works best. It's easy to share between people who have to review your application, and it's also a format that ensures that people who quickly have to fill and archive your application know how to do that
A community question
This question was asked by a community member for the second Service Design webinar.