Overview

Interviewing for software engineering role at NYC office.
Has 4 total rounds.

Round 1

Question

Tell me about the a exciting problem you had to solve recently.

Question

Write a producer class, which takes messages and sends them to a pre-defined network endpoint. Contraints:

• The class should have some caching in place, that it should not try to send message as it gets them.
• The class will be instantiated from a single process. The instance may be shared across multiple processes.
• The constructor should take 2 arguments
  • First argument should be the max count of messages. At any instant producer cannot hold more messages that this count.
  • Second argument should be the "max time allowed for each message to be held". At any instant, the producer cannot hold any message to time more than this argument.
• The class should expose a public "SendMessage" API which takes a string as a message, and sends it.

Discussion

Try to get more constraints, such as what is the expected least count for the second argument to the contructor.

Round 2

Questions on architecture

• What is virtual memory and why is it needed?
• Describe the uses of "private, protected and public" in objective oriented programming.
• What is the difference between process and thread.
• Describe issues with concurrent memory access by various threads and how to resolve it.
• Describe the neccessity for virtual methods.
• Why C++ desctructors are genrally declared virtual.

Question

Some behavioral questions arond my previous work.

Question

Write an API that takes input string in the form of "<2 characters denoting the length of next message><message>" and prints the message.
Input is guaranteed to be valid.

Example

PrintMessage("02bc101234567890") prints "bc1234567890"

Follow up

The input is valid, but is broken across multiple invocations.

Example

PrintMessage("02bc1012345")
PrintMessage("67890")
This should also print "bc1234567890"

Question

You have a singly linked list, where the tail could be null, or could be pointing to another node of the linked list.
Write an API to return true, if and only if, the tail is pointing to another node of the linked list.

Question

Given (n+1) and (n+3) are prime numbers, prove that n+2 is always divisible by 6 (with one exception).
Explain the exception as well.

Round 3

Question on architecture

• linked list vs. arrays
  • Conceptual difference
  • Big O notation for insertion
  • Is there a perf difference for "summing up all elements" for large structures (count of elements > 10^6). If yes, estimate the difference.
• How do you start on a new projects.
• How do you estimate a project's success.
• If you authoring a service, what metrics would you add to the service.

Round 4

Question

• Design google maps, optiomize for faster "shortest time" quries between 2 points.
• The complete map data could not fit into one machine. How would you parition the data to fit on mutiple machines.

Question

Given a list of 3 co-ordinates of n triagles, such as the triangles cover some cartesian space completely without overlapping, write a function that takes an point in the 2-D space and returns the triangle that encapsulates that point. Return -1, if no such triangle is found.