S&T interview questions

What does Response.Redirect do, EXACTLY, what code does the browser receive, what's the name of the key that holds the url? What kind of redirects do we have? What is the difference between them?

What does the optional parameter in Response.Redirect(“url”, true) do, in MVC5?

What is an application pool? When does it recycle automatically?

What is an IIS handler?

How does one register an IIS handler? (aspnet_regiis -i)

What happens server side when a request reaches the ip:80, how does the payload reach a specific application?

What is the easiest way to achieve stack overflow in C# (write code)

What is the difference between a stack and a heap?

What is a string (reference type), can we box it? What does StringBuilder do?

If the IIS crashes (and not only a specific app pool) how would you begin debugging?

How do we parse w3c logs? (LogLizard), can you log request/responses in w3c? Why? List common w3c log properties.

How do we parse windows OS memory dumps? What can be found within a parsed memory dump?

How does IIS know where to route incoming requests? (to a specific vhost) - bindings

Know your polymorphism: public class Drawing { public virtual double Area() { return 0; } } public class Square : Drawing { public double Length { get; set; } public Square() { Length = 6; } public override double Area() { return Math.Pow(Length, 2); } } public class Rectangle : Drawing { public double Height { get; set; } public double Width { get; set; } public Rectangle() { Height = 5.3; Width = 3.4; } public override double Area() { return Height * Width; } } class Program { static void Main(string[] args) { Drawing square = new Square(); Console.WriteLine("Area :" + square.Area()); Drawing rectangle = new Rectangle(); Console.WriteLine("Area :" + rectangle.Area()); } }

What is a pointer? How does string work in C++?

What is garbage collector? How does is “collect” heap memory? What is a finalizer thread?

Where can we find value types? Only on stack? What happens with stack and heap in multithreaded applications? (share heap)

When can we find a value type on a heap? (sometimes, yes, heap contains an actual object, stacks *can* contain references to objects, they are also owner thread scoped)

Whats a struct? Whats a ref struct? What is an enum? Is it on a stack or on a heap?

Is Dictionary thread safe? How can we make it thread safe (either by using lock or by using a thread safe version “SynchronizedDictionary”)

What is reflection?

What is a dynamic proxy? How can we intercept method calls using a dynamic proxy?

What kinds of state do we have for ASP.NET?

How would you implement an application wide logging strategy? (by intercepting method calls via dynamic proxy)

How do the server and the browser exchange cookies? Where is the cookie located client side?

What would be the best way to implement localization/translations for an MVC5 app? (read the browser agent locale from the request? Use a cookie? Use “/en/” in an url? Where in the MVC lifecycle would we place such code?

How can we inspect http request and response? (by using a proxy like fiddler)

List all default http header properties

How does http cache work? (Etag, last modified, http status codes for these?)

What is the [OutputCache] MVC attribute? How does that work?

What is “factory pattern”, provide an example of a problem being solved by using this pattern

Message pattern Unit of work Repository pattern Service pattern Strategy pattern Specification pattern DI / IoC Singleton

What is the size range for a “numeric” datatype in mssql? (2 pw 38+1 to 2 pw 38 -1), what is its storage size? (5-17 byte), the same for other sql data types

What is the mssql page size (8kb), how many pages per megabyte? (128) what is the size of a page header? (96kb) how can we deal with “row-overflow data” (include them as key or nonkey columns of a nonclustered index), they provide you an example table and query, calculate whether you need to include columns via “include” in relation to 8000 bytes of available memory before overflowing, or you need to make the table columns smaller in size, or change their type (what are the rules regarding this)

What is a logical read? What is a physical read? How does cache affect them? Does tempDB come into the picture?

What do excessive logical reads signal? (low memory (so called “memory pressure”) and index scanning)

How do we check those? (select * from sys.dm_exec_query_Stats)

Difference between RID lookup, index scan, index seek? Explain execution plans provided, decide how to optimise

How does MSSQL compile/sign CLRs? (probably provide correct sql statements as well)

What are the various types of UIDs?

Is a GUID a good choice for a PK? What about index size?

What is a btree? What is a “leaf”?

What is a lock? (not a deadlock)

What hint can we use to skip a locked row? (SKIPLOCK)

What is “read uncommitted”?

You have a large production table (millions of rows), you need to delete all rows, which statement you use and explain why (truncate, do not delete)

You have a large live production db with rows being inserted regularly, you need to delete all rows EXCEPT for a region of rows that you want to keep, write a sql statement that would do this *optimally*

When to use @@IDENTITY and when @SCOPED_IDENTITY

What is an indexed view?

Why do we shard tables? What problem are we solving, how?

What is “code link”? What are symbols? What is a .pdb file?

Where does .net store symbols? Where does MVC5 store pre-compiled razor views? Why do we sometimes need to delete these?

CAP theorem (explain), how is atomicity ensured for an (for an example) update statements