High-Level Design
Design the core of a location-based dating app: a user sees a feed of nearby candidate profiles, swipes like or pass on each one, and when two people like each other they match and can start talking.
In scope: the candidate feed, recording swipes, and detecting mutual matches. Post-match messaging is the <a href="/problems/chatapp/solution" target="_blank">Chat / Messenger</a> case, treated as a separate service downstream of a match. Profile photo storage and delivery are out of scope — assume large blobs served behind a <a href="/fundamentals/cdn" target="_blank">CDN</a>. Ranking quality, payments, and identity verification are also out of scope.
What a strong answer sounds like
State the decision, connect it to a requirement, and name the tradeoff. Keep the design focused on the workload in the prompt.
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