Qualcomm Design Engineer interview questions

I applied online and contacted by the hiring director for phone interview. The hiring director gave some introduction about Qualcomm long term plan of the project. Afterwards, I introduced myself and went through my CV. Later on, the Analog IC Design Engineer asked some basic Analog Design questions as follow: 1. What is the purpose/advantages of having multiplier for MOS design (1:M)? 2. What kind of simulation tools that you use for your design (SPICE, Spectre,Monte Carlo, etc.)? 3. What is Early Effect? 4. What is the body effect transistor? 5. Please explain about PAM-4 Ser-Des of your project. 6. Why do you use Gray Coding? 7. etc. (Everything linked to my CV)