Request Per Second

Data Store Characteristics
    - size / growth rate
    - latency / bandwidth
    - availability / consistency

Cache
    - size
    - expiration

High Level Design
    - failover



Top Facebook System Design Interview Questions
1. Design Facebook News Feed
2. Design Facebook Status Search
3. Design Live Commenting
4. Design Facebook Messenger or WhatsApp
5. Design Instagram


1. Design Proximity Server
2. Design Typeahead Suggestions
3. Design Top N Songs
4. Design Privacy Settings at Facebook
5. Design Web Crawler

Learn more about the design goals, scale estimations, high-level design overview, and detailed architecture diagram of these problems in this video - youtube.com/watch?v=Hq8pZ8G2Lm8

Part 1: youtube.com/watch?v=hykjbT5Z0oE




## coding

- find target in chess board with given start position of knight

- Given an integer array and an integer K, find the number of sub arrays in which all elements are less than K.
    - Follow up
        - Given an integer array and an integer K, find the number of non overlapping unordered pairs of sub arrays in which all elements are less than K.