Cognizant follows systematic interview process. They calls candidate between required experience range for dotnet, java and other technologies.
Process:

1. Once you reach there office. They collect your resume along with Photo.
2. You need to mention technology.
3. Calls candidate based on in time.
4. 1-2 rounds of technical interview.

Interview questions for dotnet candidate:

They divided the interview into 4 categories:

1. OOPS
2. .NetFramework and C#
3. WPF
4. DataBase and Agile

OOPs
Difference between Abtraction vs Encapsulation
What is Polymorphism
Interface vs Abstract.When to use what
Same method in interface, how to implement and call it.
Use of static constructor?
virtual and override keyword

C#
what is use of new keyword
when to use yield
Delegates VS Events
what are Generics
Extensionmethod – with example
Finalize vs Dispose- which handles managed/unmanaged code.

WPF
What are Dependency Properties?
Attached properties
Converters
Static resource vs Dynamic resource
There is tabcontrol and we have 2 different controls inside it. Now how to load control at run-time. -DataTemplate Selector
DataTemplete vs Control Template
Type of Bindings

Agile and Database
What is Scrum
Estimation
Retrospective meeting
SCrum of Scrum?

What is Self Join? SQL query for it.