# Quaro webinar

- 80: 20 rule for active users consideration
- DAU - daily active users
- MAU - Monthly active users
- CAP theorem
- Sharding using master and slave , read from slave
- Active passive load balancer, active active load balancer
- Layer 7 load balancer or layer 4 in oss
- Vertical sharding, horizontal sharding
- Consistent hashing
- Sharding startegy
- Hot shards
- celebrity handling
- sticky session
- stateful app server for news feed
- user id based sharding to customize feed for user

###### tags: `System Design` `Webinar`