Design of Instagram

Define the API and metadata model for the media-sharing exercise. Keep object bytes separate from their records, and make visibility, retry handling, and pagination part of the contract.

High-level design

The system must support uploading, viewing, and searching media. Additionally, users can follow one another. This requires a robust storage layer to persist media and a retrieval mechanism to fetch data on demand.

API design

We will implement REST APIs for the following features:

• Post photos and videos

• Follow and unfollow users

• Set or remove a like

• Search photos and videos

• Generate a news feed

The sketches include a userID, but the server must derive or validate the actor using authentication. Repeating a post or relationship mutation needs a stable identity or desired-state operation. Client-supplied user IDs alone are not authorization.