Was a week-long process with 2 interviews; one virtual and one on-site in their North Reading, MA. Their interviews typically take longer than this based on a previous interview I had and what I've read online.

First round was a mix of 1-2 behavioral questions, and a few technical questions. Second round was with 2 software engineers and the manager (40 minutes each).

The engineers asked a mix of behavioral and technical questions, with majority being technical. Most of the conversations I had with the manager were casual and behavioral, and ended with a tour of the facility.

They were having a barbecue that day, and were very kind enough to offer me food. Overall, a very positive and friendly experience.

First round:

Behavioral: *Tell me about a project you worked on. *Are you familiar with our company?

Technical: *Tell me about some concepts in object-oriented programming. *What is an abstract class and function(s)? *What is an interface? *What are virtual functions? *What is the static keyword in classes? How would you use it to implement a counter to track the total number of objects of a class instantiated? *You have a memory-mapped register with the 4 least significant bits controlling whether or not a specific relay is on or off (bits 0 to 3 respectively turning relays 0 to 3 on/off). Write me a function that takes the relay number and desired state (on or off) and turns that specific relay on or off. Write me a function that takes a relay number, reads the register, and returns if that relay is on or off.

Second round:

First interviewer: *What is a stack (both as a data structure and in the context of memory)? *How would you implement a stack using c#? *How does the garbage collector in c# work? Why would you want to set references to null? *Please describe and give UML models of a project you worked on (block diagram, state machines diagram, user-interaction diagram, activity diagrams, etc).

Second interviewer: *How familiar are you with c#/c++? *Talk about previous experiences using both languages. *What is a deadlock in multi-threaded programming? What is a mutex? *You have a base class which implements a bank account that has the ability to add funds, withdraw funds, and read account information including account ID, balance, and full name. If you withdraw and reach a negative balance, 20 dollars are further deducted from your account. A derived "gold account" class does not have this overdraw functionality. Please implement this using c#, c++, Python, or pseudocode. *Further bit-shifting embedded systems question. Nothing too different from first round.

Manager:

Mostly casual conversation. Positive experience. *What do you want to get out of this experience? *Tell me about your previous role.

And talked about their various open projects to see which is of interest/best fit.