Offer Matching API Design

You work as a software engineer at Credit Karma. The team is tasked with building a backend API that retrieves and serves relevant financial product offers, such as credit cards, personal loans, and auto loans, based on user profiles.

When a user logs in, the API must fetch all available offers from multiple partner services, filter them using factors like credit score, and return only the most relevant auto loan offers if the user expresses interest.

How would you architect the API endpoints and backend logic to support this functionality?