Dot net concepts
2) OOPS concepts
3) Thread, Thread Synchronization, Process, Multi-Threading etc.
4) Memory management (e.g. stack, heap, memory leak, garbage collector etc.)
5) Good command on SQL server queries, indexes, stored procs, keys, Data consistency
6) Command on Linux commands
7) Code Debugging skill on windows and Linux boxes(platforms)
8) Knowledge and experience required in GDB, core dump etc.
9) Good analytical and reasoning skill.
10) Problem solving and grasping power and interested to be learnt new things (technology, process, design etc.)