I received an interview call for a CRM team opening in Bangalore. My friend at Microsoft referred me, so I got a direct interview call instead of a Skype round. There were four rounds, with the last round being a manager round. Each round included some algorithm design questions and some system design questions. Some of the questions were:

1. Calculate a given expression consisting of /, *, +, and - operators only (checking for multi-digit numbers, unary minus operator, divide by zero, etc.).
2. Serialization of balanced and unbalanced binary trees.
3. Some general linked list and tree-based questions.

Design a system that takes important input data and information about its importance. This system should send the data after deciding on a transfer protocol and encryption algorithm. The main question is how to decide on the protocol and encryption algorithm. Also, the system should be adaptable so that in the future, new algorithms and protocols can be added without many changes to the system.