design a chat app mobile system design
Design a chat app for a mobile system design interview
Design a mobile chat app with delivery state, offline queues, sync and reconnect behavior.
Who this is for
Mobile engineers practicing a common system design prompt.
What to cover
- Message identity and ordering
- Offline send queue
- Delivery and read state
- Reconnect, retry and observability
The useful result
A chat design that stays understandable across failure and multiple devices.
Use the keyword as a starting point, then judge the work by whether it solves the reader's actual problem. A strong answer names the context, the decision, the closest alternative, the failure mode and the evidence that would change the recommendation.
