Meta | SWE | USA | result pending

I have given final rounds of interview for Meta for the post of SWE.

2 x Coding rounds 2 x Behavioural rounds 2 x System Design rounds

Coding-1: (40 minutes)

1. Find the root the of the tree from given list is random elements in Array.
2. Find the route from 2D matrix from top left to bottom right element.

Coding-2: (40 minutes)

1. Array depth sum with multiple inner arrays.
2. Write the API to get, put, remove and "last" key,value pair, last should return last accessed value other than remove operation.

System Design: (40m) Desgin library for download operation for mobile devices.

I feel like could have done better so I don't thing I'll get positive response.