Ciena came for campus placements at my college in Nov' 24.
Offer: Internship 6 Months - Jan to June 2025. 35k for B.Tech and 40k for Masters

First Round: Online Assesement

3 sections

1. Coding Round: 25 Minutes

Q1. Check if a number's binary representation is palindrome or not. This question only had language option in C. I repeat no option to code in any other language than C.

Q2. Some students and their heights are given, then an arrangement is given about how they are standing, print the indexes which are standing at the wrong index if the students have to stand heightwise increasing order. This question was allowed to be solved in C++.

2. Programming Languages Round: 30 Minutes
   This was a mcq round where we needed to answer a lot of syntax based questions. A lot of confusing pointer based questions were asked, references, pointer arithmetic, function pointers etc. Basically deep questions about syntax of pointers in C language.

3. Aptitude Round:
   These were 5 basic aptitude question that high school students can solve.

Face to Face Interviews

Round 1:
First I introduced myself, where I'm from. Then the first question was to write the syntax of a void function pointer that takes input of two integers and then assign this function to a real function
Other questions:

1. Malloc Syntax related question, what does malloc return.
2. What are static variables, difference between static and global variables
3. If a struct stores 2 integers and 1 char how much memory does it occupy, follow up : Where is that padding stored internally ??
4. Find the middle of Linked List, follow up : If even number of nodes, what would the code return how can we configure it ??
5. How to avoid deadlock : 4 conditions
6. Difference Between struct and union
7. Reverse the words in a sentence write code on paper.
8. Explain one project in detail
9. Some super hard pointer related questions
10. Difference between semaphores and mutex
11. Difference between declaration, initialization and definition for a variable.

I really struggled with lot of pointer syntax questions (where to place & and *) and was nervous. In between interviewer asked what topic am I confident in and then I said data structures and algo. he then asked difference between struct and union, I couldn't answer and the interviewer said but these are data structures ;((

Round 2: 20 out of 35 Students shortlisted

First basic introduction

1. If we use malloc(0) what would happen ??
2. Write syntax to declare an array of size 10 that stores pointers to integers, and then declare a pointer to an array of size 10 that stores inegers.
3. A syntax like

int x = 10;
int *ptr = x;
++(*ptr);

what would *ptr return ??

4. Find duplicate element in an array containing numbers 1 - n where 1 element has a duplicate: I started with writing cpp code but was told to write c, Then I wrote the standard slow pointer fast pointer code for this question. Then had to explain in detail how the code would work, like when the cycle is detected and then when the duplicate element will be detected. Then would the code run in o(n) or why not. I said it would detect it in o(n) but the interviewer asked are u sure, I said yes. Then he said aren't the pointers pointing to indexes randomly, then I changed my answer that this code might lead to running the loop more than n times.

5. Puzzle: If there are 4 jars with infinite 10g balls and 1 jar with infinte 9g balls. If we can only weigh once how would we detect the defective jar.

6. Mutex why do we use them.

7. Static variables, ever heard of volatile keyword why do we use it. How exactly does compiler 'optimize' a variable in case we don't use volatile keyword.

8. Discussion on have u ever studied compiler design, written assembly code. I studied 8086 processor so talked about that.

I answered most of the questions and puzzles, I think I got stuck a lot of times and confidently gave the wrong answer to some pointer based questions. I thought the 2nd Interview went a lot better than first.

Result: 10 out of 20 Selected. I got rejected. The experience was good, interviewers were polite and friendly.