Vidder interview questions

Written was designing a system and coding some of the system internal modules. Once you qualify for the written, then interviews were mainly to gauge candidates grasp on C++ internals & usage, system designing and Interpersonal Skills. Some of the specific questions I remember given below: Smart Pointers Implementation with reference Count(basically internal implementation of all types of Smart Pointers:shared/weak/unique/auto etc... Static variables usage in Templates Thread Safe Design Patterns: Singleton/observer/MVC Data Structure Problems on Strings, Hash Maps and Trees Web Server designing and scaling Past Work-ex, problems faced and achievements STL and Boost Library containers, functional & algorithms usage and rational of usage while designing Design own vector class with custom Allocator Some unheard Puzzles: Mainly to understand the thought process rather than looking for definitive solutions Multi threading concepts and practical scenarios, a problem on the same on the lines of reader writer buffer management System Programming concepts and some system calls internals