C-DOT Interview Experience For M.TECH,CSE (On-Campus)

C-DoT came for the post of Research Engineer at IIT BBS. There were 2 technical rounds and 1 HR round

In the first technical round(online) they mainly focussed on technical subjects. The following questions were asked in

Round 1(Online)

• what is kernel
• difference between kernel and OS
• how mode bit shift happens(who does , how it does everything)
• difference between privileged and non-privileged instruction, fragmentation, why the logical address is required
• basics of oops-abstraction, overriding vs overloading with example
• networks TCP error control works and the fields in TCP header and their use such as PSH, URG
• out of nowhere, they asked me about SDLC gave certain scenarios, and asked me to choose which model was good for this
• it went on for around 40mins and I was shortlisted for the next round.

Round 2(Offline round in front of 3 panel members)

They asked my favourite subjects and I intentionally kept Computer Networks at last as soon as they heard they gave me a scenario:

suppose you are sitting in your lab connected to your institute’s internet. You have to gain access to a system in the C-DoT organisation.

First, they gave me a pencil and paper to sketch out my thought process which I did but after that, they handed me a laptop and asked me to gain access to the system on the spot. I was in a state of shock ( 1 minute of silence and staring was maintained from both ends). After 1 min I returned the laptop saying I didn’t have any hands-on experience but said we could make use of ping and they started asking about ping and all.

• They also asked if you are asked to gain access to a system in your lab now, then how will you do it?
  (I didn’t mention anything about Hacking or any such stuff in my Resume)
• Coming to OS they asked
• Do shell scripting again handing the same laptop to which I replied I don’t have any hands-on experience.
• Then they asked certain commands in Linux (use of -g), how to compile using GCC and rename the .exe file, and import libraries such as math. h from terminal
• What is ELF and where it is used?
• Various other LINUX commands that I haven’t heard earlier
• Certain conceptual compiler questions
• Coming to programming they asked about
• RED black tree where it is used in real life
• Difference between struct and union and its use in real life
• Difference between calloc and malloc and new
• Create a structure with a 2bit variable (using a bitwise operator)
• Write a C code to add 2 linked lists using a stack(stack has to be used) and explain all the complexity
• Write a C code to find the first 2 triplets whose sum is close to ZERO
• Various C output questions
• What is segmentation fault and write a program that will generate a seg fault and what and how it happens?
• Coming to projects they only asked about 1 project which they found relevant to their domain.

Asked to go for the HR round where I got an indirect confirmation of rejection.

(I never imagined being asked to hack a system during a technical interview for a company like C-DoT, especially since I have no prior experience.)

Tip: Always expect the unexpected and maintain a good CGPA to get shortlisted