• Languages: C (4 Yrs), C++ (8 Yrs), SQL (2 Yrs), UML (2 Yrs), UNIX Shell scripts (6 months), Java (2 Yrs), Python (6 months). • Operating System: UNIX/Linux (8Yrs), Windows (1.5 Yrs), Solaris (2 Yrs). • Design Patterns used: Singleton, Strategy, Chain of responsibility, Command, Observer, Adaptor, Façade, Decorator, Factory method, Abstract Factory and Object pool. • Data Structures: Arrays, list, Binary tree, Heap, Graph, Stacks and Queue. • STL: map, vector, list, deque and multimap. • IPC: Socket and Shared memory. • Multithreading: POSIX pthread library. • Network Programming: Socket programming. • Architecture: 3 tier, 2 tier, MVC. • Corba : IDL definition, Server code implementation and client code to call server. • Design tools: Rational Rose and StarUML. • Protocols: Diameter, TCP, ICMP, UDP. • Network analysis tool: Wireshark, TCPDUMP. • Network traffic generator: Seagull. • Linux utility for performance/process management: mpstat, vmstat, uptime, free, ltrace, ptrace and objdump. • Source code management tools: ClearCase, Subversion, CVS. • Design and Code review tool: Code collaborator. • Requirement management tool: DOORS. • Static analysis tool: Coverity.