Freecharge Interview Experience | Set 2 (Experienced)

Round 1:

How to make class immutable
Singleton design pattern
Lru cache implementation
difference between abstraction and encapsulation
types of polymorphism

Round 2:

Discussion about current project
Concurrent hashmap vs synchronized map in detail
Left view of tree

Round 3:

complete architecture of current project
find nth max salary without traversing complete table
in binary tree print all nodes at distance k from given node
design car manufacturing company software sysytem
clustered indexes in sql