I had two telephonic interviews.

The first round was with HR. I was asked questions mostly from my resume, including:

• Projects I have worked on
• My short-term and long-term goals
• Why I was interested in MathWorks

The second round was entirely technical, consisting of mainly two sessions:

• Control Systems: This session covered PID controllers, state-space equations, system stability and instability, region of convergence, pole locations, and damping conditions of second-order systems.
• Programming Skills: This session included questions from MATLAB as well as C/C++.

Some typical programming questions were:

• What is local scope and global scope?
• What is #include?
• What is the difference between using #include <stdio.h> and #include "stdio.h"?
• What is recursion? Give an example. How does it terminate?
• How does the system handle recursive calls?
• What is the malloc function? What is the difference between malloc and other memory allocation functions in C?
• How do you preserve MATLAB settings across sessions?
• What is the difference between a script and a function in terms of their workspace?
• What does A' do? How do you take the transpose of a matrix in MATLAB?
• What is the difference between * and .*?
• How do you take the inverse of a matrix in MATLAB?
• How do you think calculators give answers to mathematical operations like SIN and COS?
• What are virtual constructors, destructors, and polymorphism?
• What are MEX functions?
• Where are global and persistent variables stored?
• Give two different ways to access an element in a matrix.
• What command would you use to get two different axes on the same figure?
• What are cell arrays?
• Is MATLAB column-specific or row-specific?

There were many more questions, including some from linear algebra.

Many basic questions from MATLAB were there, which I couldn't answer.