5 System design questions

1. We have a facebook like app that shows posts along with the count of friends one has. Given the database schema how would you return the count of friends a person has.

This was not how would you design the sytem but like how would you write then query which was confusing to me.

2. There is a shared document app that stores the document used by people in one server. The server is selected using round robin approach what problems do you see.

I went with uneven distribution of documents based on size and geolocation being an issue since a user in one country could have documents stored in another server.

3. We have a docu-sign app that sends a verification when a document is completly signed(500+ signatures). We had a glitch in system and some notification were not send to user.We now have a database table that contians all documents that were fully signed and logs indicationg which document notfication were sent for. The glitch has been rectified how would you consolidate the issue

4. Given these secanrio choose weather eventual consistency or strong consistency is required?
   1) Metadata for a movie (eventual)
   2) Activity of a user for analytics (eventual)
   3) Bank transaction with payments and balances (strong)

5. There are a number of nodes in system where each can process X requests and a process cannot be mark completed until all the nodes complete it. What is the max process that can be processed at a time .

   I chose the slowest node as the answer in all processes.
   Follow up how would you rectify the problem.
   I went with add a kafka queue and horizontal/vertical scaling.

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Word search problem with limitation of going down or right. But instead of idnetifying if word exists we have to get the path.

I messed up in backtracking for the path so practice path when word is found