This was a contract position a staffing agency got in touch with me about. The phone screen was scheduled fast. It was questions about experience on the resume and general C questions, such as:

• How do we allocate memory?
• How do we free memory?
• What do we do once memory is allocated?
• What is a circular buffer?

Later, I was brought on-site where I met three people.

The first person was talking about machines they make and about the machine they would make in the future. They took me to the posters with the machines. They did not ask any questions.

The second person went over positions in my resume and asked three questions:

• How would you organize a class of random polygons that could include arches in polygons, circles, polygons, etc.?
• Add a new element into the binary tree.
• You have an app with two threads: one is very busy, the second is lightly loaded. How to make sure the "light" thread would get resources.

Apparently, the interviewer did not hear the answer he expected.

The third person, probably a senior manager, went over my CV asking questions about previous experience.

• Write a code in C which will check if a given word is a palindrome.

The next day, a recruiter from the staffing agency called me and said there would be no offer. The interview was very easy, as if the interviewers knew the result already.

You have an app with two threads. One is very busy; the second one is lightly loaded. How do you make sure the "light" thread gets resources?