System Design Visualized
Lesson 10.2

Gathering contact info

Play this lessonThis lesson comes with an interactive animation you can break and a chapter quiz.

To send notifications we need device tokens, phone numbers and email addresses. When a user installs the app or signs up for the first time, the API servers collect this info and store it:

The rest of this lesson is part of Pro

Pro unlocks every lesson with its animation, code challenge and quiz, plus every interview problem. ₹299 a month or ₹1,999 a year.

See Pro

Remember it, then prove it

Create a free account to save your progress, get spaced-repetition reviews of what you miss, and design real systems in the interview simulator.

Start free