Designing an Instagram

A product lead describes the app in one sentence. "People post photos, follow each other, like and comment, send private messages, and join groups."

Turning that sentence into tables uses every rule from the earlier chapters. This case study builds the whole design, from that sentence to running SQL.

What the system must do

Six capabilities, taken from what people actually do in the app.

Manage accounts, with a username, contact details and a profile picture.

Publish posts with a caption and a date.

Follow other users, in one direction