https://www.youtube.com/watch?v=VJpfO6KdyWE&ab_channel=Exponent

Functional Requirements

  1. Upload/download/view images from a client (mobile/web)
  2. Users follow other users.
  3. Generate a feed of images.
  4. Scale: 10 million users.

Other:

  1. search based on titles

Non-functional requirements

  1. AP
  2. Latency:
    1. For poster: low. <500ms.
    2. For reader: medium. 5s.
  3. Highly reliable. Redundancy.

Estimation

Storage: 1e7 * 2 * 5MB / mo = 1e8 MB / mo = 100 TB / mo = 1.2 PB / year