50 + Interview Questions/Experiences of TCS DCA April 2021

Hello Everyone!

This is the second part of the article - Interview Questions asked in the TCS DCA Exam. To know more about the DCA Exam, its pattern and remaining interview questions, kindly check out the First Part.

16) Duration 25 Minutes

• Introduction 
• Why digital? 
• Cloud and cloud computing 
• Machine Learning. 
• Explain all algorithms you know. 
• Deep learning 
• Different algorithm paradigms and give two examples 
• N queens problem (Explanation) 
• Travelling sales person (Explanation)

17) Branch - Mechanics
Preferred language - Python

• Introduction 
• List vs tuples 
• Do you know any other data structures? 
• OOPS concepts and real life examples 
• Algorithms/Logic for basic problem statements 
• Examples of new digital technologies

18)

• Project in depth 
• SQL query to fetch odd rows from the given table 
• Why we use cloud computing? 
• OLAP vs OLTP 
• Difference between having and where clause 
• Data structures and their types 
• Searching, sorting algorithms 
• Best of the algorithms with their complexity 
• Quick sort and binary search logic

19) Branch - ECE
Duration 50 Minutes

• Introduce yourself (I explained about 3-4 minutes)
•  If you have 10M subscribers in your YouTube channel will you be still working with TCS? (As I said about my YouTube channel in introduction) 
• If we put you in a night shift at a place and you were unable to work with both channel and office work, and you are getting huge amounts from your channel then what will you choose? TCS job or YouTube channel? 
• Who is the CEO of TCS? 
• What are mutable and immutable datatypes in python? 
• Write a program for binary search in python and explain the procedure? 
• Explain Bubble sort? 
• Do you know python? 
• Pickling and unpickling in python? 
• Generators and iterators in python? 
• Difference between list and tuple? 
• Do you know about DBMS or SQL? 
• What are joins and how many types are there? 
• What is a primary key? 
• Difference between primary key and unique key? 
• What is foreign key? 
• Query to get unique records in a table? 
• Query to get first name in customers table in uppercase? 
• How do you convert date(dd/mm/yyyy hh/mm/ss) to (dd/mm/yyyy)

20) Branch - EIC
Duration 30 minutes

• Introduce yourself 
• Tell us about project. 
• We discussed project about 20 min along with code and algorithm used in project. 
• After that they asked me about my interest in further studies and research kind of things. 
• What new technologies you are willing to learn and do you have tried any of them?

21) Branch - CS
Duration 25 - 30 minutes

• Questions on the ML, models, algorithms in ML. 
• Logic for some problems in python. 
• Some concept of Python
• Decorators, lambda in python
• Difference between html 1 and html 5. 
• Basic question on react JS
• Rate yourself in each of the technology

22) Duration 45 to 50 minutes

• Asked about technologies on which I've worked
• Asked to code in python without using inbuilt libraries where you have to take the date of birth of a person as input and have to calculate the age of a person in years, months and days and also calculate the remaining days for next birthday
• Python code to take list of integers and print list of square root of those numbers
• Python libraries used in the project
• What is cloud computing 
• Cloud services 
• Deployment models
• AWS lambda
• Rest whole interview revolved around cloud computing only
• What's the meaning of highly available in CC?
• Which services are IAAS PAAS SAAS in AWS 
• Why AWS 
• Horizontal and vertical scaling
• Advantages of cloud computing

23) Branch - CSE
Duration 20 minutes

• Introduction 
• Project and your role in the project
• What problem you solved in your DCA exam
• ML basics
• Code to show multiple inheritances
• Code to reverse the words in a line separated by “.” like " my.name.is.this " to " this.is.name.my"
• Various sorting techniques with their complexities
• Tree traversal techniques 
• Singly circular linked list 
• Overloading and Overriding abstract data types 
• Constructor
• Primary key and unique key difference. 
• Preorder traversal
• Can we write static public void main in java?

24) Branch - CS
Duration 20 minutes

TR -

• Introduction
• Asked me what my project is about
• Told me to explain each and every module used
• Django framweork (intermediate used in my project)
• Problems faced in project
• C, Java (basics)
• Why is main function static in java?
• What is the use of static keyword?
• What coding language used in dca?
• Random function in Python (in depth)
• Tell me about other digital you know (mentioned VR, AR, AI, ML, IOT)

HR -

• What is IoT?
• Modules,sensor you used in IoT project
• Difference between nodemcu and raspberry pi
• Difference between AI, ML
• Supervised vs unsupervised
• What is deep-learning?

25) Duration 30 to 40 minutes

• Introduction
• About project (ML based)
• Questions about the various concepts used in the project like LSTM, vanishing gradient problem, backpropogation
• Different ML libraries used in project
• Basic ML questions like bias variance tradeoff 
• Basic python questions like lambda functions, inheritance, init function, etc
• Which technologies would you use to digitalise the functioning of a covid testing pathology lab?
• SQL query to find the second minimum salary from a table.
• What is data load balancer multiprocessing in computer
• How does Amazon and flipkart manage their cart related functions in the backend.
• Questions related to web development (mentioned project) 
• 2 logical aptitude questions
• Decorators in python 

26) Preferred language - Python

• Introduction
• Python questions
• List, dictionary comprehension, lambda, generators in python
• List vs tuple
• How to create list tuple
• Set vs dictionary
• Is set is ordered?
• Convert the given function into lambda function -
def mul(a,b):
      return a*b

27)

• Some questions on project
• What was your role, brief introduction about project , how is your application different from others?
• Next on AWS(As mentioned in resume)
• How to launch EC2?
• Use cases of cloud
• Cloud service providers?
• Scaling?
• Test case: In one country at night your users are high then how u can allow traffic how can u scale?
• What is Kubernetes, docker?
• Why you chose AWS?

28)

• What is AI, ML and DL? 
• Algorithms of ML
• Types of learning
• Blockchain? 
• What is it? How it works? Where it is used? Where it can be used?(Use cases)
• Latest technologies like cloud , data sciene, IoT revolve around what exactly?
• What are you going to learn next?

29) Branch - CSE

• Self introduction
• Prime number logic (orally)
• SQL queries 
• DBMS questions (acid property with real time example, normalization, join)
• Angular technology (Mentioned about the internship in angular in introduction)
• Oops (4 layers)
• What do you know about digital technology?
• Open to work upon which technology?
• Willing to relocate?
• Java questions in depth.
• What's your preferred language? Also asked why everyone is choosing python.

30)

• IoT definition
• IoT drawbacks 
• Modules used in IoT
• Difference between Arduino vs raspberry pi?
• Why did you choose particular micro-controller for your project?

31)

• Tell me about yourself
• Oop concepts
• Fibonacci series code
• Supervised vs unsupervised
• Overfitting in ml
• ETL tools u know
• Cloud you know
• SaaS
• AI

32) Branch - CSE
Duration 40 minutes

• Introduction
• 4 pillars of OOPS
• Lambda function
• Given code to write lambda function for that code -
def fun:
     mul(a,b)
• Output of the following-
(a) 5//2
(b) 5/2
• Stack
• Priority queue
• Generators in python
• Decorators in python
• Where vs having clause
• SQL queries for finding 2nd lowest salary
• Digital technologies 
• ML and AI difference
• IOT
• What were the subjects in your final semester
• DBMS vs RDBMS
• What technologies  you would love to work in digital field
• Cloud computing 

33)

• Introduction
• What is Django 
• Django vs flask vs pyramid 
• Django models, static files in Django
• wsgi and asgi in Django
• Database in Django

34) Branch - IT
Duration 30 to 40 minutes

• Introduction
• Questions on the project (Project was on deep learning so they asked about the functions I used while building my project)
• I have mentioned Django in my resume so they asked how to set up a database connection in Django
• Python list comprehension
• Shallow copy of '='operator for lists
• A program in python to reverse words is a given string.  Input:'hello world' Output:'world hello'
• What do you expect from TCS in 5 years ?
• Blockchain basic idea

35)

• Questions from ML
• SQL queries
• Basic java question
• Simple codes (Bubble sort and reverse a string)

36) Duration - 30 minutes
Branch - IT

TR -

• Tell me about yourself
• Asked about the project
• Java based questions as it is mentioned in resume
• OOPS concepts
• About, Constructor, Abstract Class, Inheritance, Interface
• Difference between Overloading and Overriding
• A code was given and asked to explain the flow, memory management, how does it internally works
• Synchronization in java
• Compile and run-time polymorphism
• Questions on Internship Project
• Explain the project. What you have contributed?
• Scenario based questions :-
• What is encrypted , as you use WhatsApp, you must have seen it
• If you have given google excel data sheet and data entered must be retrieved in database , then how would you do that? What will be the approach and algorithm?
• What is the algorithm used for facebook the elements like Story, Event or any other fields
• Singly linked list
• How would you display the middle node value without traversing the whole list
• Some commands on SQL
• Definition of  AI, ML, Cybersecurity
• Difference between supervised and unsupervised learning
• Collections in java

HR and MR -

• How is your lockdown going
• What did you studied in past 6 months
• Did you go through any courses of ML or any digital technology
• I'm a basketball player as written in resume, so they asked what positivity you got from it?

37) Branch - CSE

• What  Is ML?
• Have you worked in any of this technology?
• What do you understand by digital technologies?
• What is SQL and DBMS?
• SQL queries
• What is stack and queue?
• What is HTML, CSS and JavaScript?
• Have you worked on any front end technology 
• Difference between HTML JS and JavaScript frameworks 
• What is stack and queue and have you implemented any of it?
• Program for factorial using recursion , while loop and for loop 
• Program for while loop 
• What is natural number 
• Composite number prime numbers even no and odd numbers
• Any problem with relocation ?
• Any problems with working with any technology 
• Any problems with night shift 

38) Branch - IT

• Majority questions on project
• Code was asked and you can tell the logic orally
• Armstrong no and reversal of string was asked
• My project was on R which is a statistical language and I have used data set to train the model to give output
• So ML questions were asked
• Supervised unsupervised learning
• What functions did you use and how R is different from excel?

39) Branch - CS 
Duration 20 minutes

• They asked some basic questions where do you live etc.
• What is your position in your class
• Asked about projects (I did 4 projects on IoT)
• Explain your favourite project and what all difficulty you faced?
• More on projects and IoT
• Language preferred (c,c++)
• Questions on them all were basics and how did you use them in your project codes.
• Overriding overloading
• C  and c++ difference
• SQL injector 

40)

• They ask about myself
• SQL joins
• About my project
• How could you learn new technologies?
• Tell something about captcha code
• Then they asked why the image was so clear in captcha code 

41) Branch - CS
Duration 40 minutes

• Projects
• New technologies (I mentioned AI)
• What is the programming language used in AI?
• Data structures- tree, graphs, BFS and DFS
• Circular linked list implementation
• Then give problem of dynamic programming and asked my approach to solve. Problem is travelling salesman problem.
• Lcs in dynamic programming
• Since I mentioned machine learning project so they ask do you know about svm
• How to split train and test data
• Basics of python- self, init, global variables, scope, mangling, inheritance
• Basics of java- garbage collection, interface, abstract class, difference between c++ and java, 
• Is java is pure oops programming language
• Your interest, hobby
• Finally they ask 2 programs pseudocodes-
(a) middle element in linked list
(b) tree height and tree traversals

42) Branch - IT

• 90% questions only coding (Example - Decimal to binary, etc)
• Little theory
• Cloud and DBMS

43)

• Introduction
• Asked about the application I mentioned and questions related to it
• ML questions like linear regression, overfitting
• One logical reasoning question
• 2 technical questions from python
• Cloud computing questions
• No coding question asked.

44)

• Self introduction
• About my project. Based on that questions
• Coding languages questions
• Questions on any digital technologies

45) Duration 30 minutes

• Data structure  
• Program for binary tree
• Java OOPS concept 
• Digital technologies  you know? 

46)

• Program for graph implementation
• OOPS
• ML known algorithms
• BFS

47) Branch - ECE 

• Mostly only programming codes 
• Bubble sort 
• GCD of 2 numbers 
• Factorial of a number 
• Given 1000 rs . What is the min number of coins of denominations 1, 5 and 10 
• Max number of subsets of length 2 from a given array 
• Big O for all these problems 
• Latest technology in digital

48) Branch - ECE

• Introduction. Questions based on it.
• Explain specific project which is asked 
• Preferred technology
• Machine learning algorithms 
• Blockchain
• Cryptography and any algorithm you know
• Machine learning algorithms used in project
• Difference between logical regression and linear regression
• Coding with preferred language
• Doubly linked list 
• Multiple and multi level inheritance program
• Searching algorithm code

49) Branch - Material science 
Duration 10 minutes

• Engineering graphics question 
• Question related to air and chemistry
• Asked for digital certificate 
• 3 programs :
(a) Identify unique number
(b) Find element in array 
(c) Duplicate the array

50) Branch - EEE 

• Asked about project it was on IOT
• Some basic questions on project 
• What you know about cloud 
• What other technology you know (I said blockchain and explained the basics)
• Cloud services 
• Preferred language - Python
• Fibonacci using recursion 
• Project 

51) Branch - ECE 

• Tell me about yourself
• What language do you know
• How much will you rate yourself in range of 10?
• Tell me about singly linked list
• Print a random number in array of size 10.
• What sorting you know
• Difference between quick & bubble sort
• Write a program for quick sort by getting random number as input
• Write a program to print current date & time
• What certification & Hackathon have you done( I mention IOT & attended workshop in cybersecurity) 
• What do you know about cybersecurity
• What algorithms you know in cryptography.

52) Branch - ECE

• Basic SQL queries using
IN
groupby
• C output finding question related to increment and decrement
• Python code to move numbers to end of string(algorithm to be explained)
• Certifications done
• Difference between logistic and linear regression
• Sigmoid function and mathematical use in ML
• How values of k are determined in KNN algorithm and why it is called lazy learner
• Indepth questions related to data analysis libraries in python
• Algorithm of principal component analysis
• Projects were asked
• What standard is provided by JPEG based on DWT ( Image processing)
• Your team has 10 members and one of your teammates did something wrong which made the client angry, what you do to solve this as a team when all of your 10 teammates have 10 varied opinions about this?
• Participation in any coding competitions and hackathons
• What libraries are used for plotting and statistical analysis, then asked the name of plots which can be used

53) Duration 17 minutes

• Self introduction 
• About IoT 
• About datascience
• Difference between arduino and raspberrypi
• What coding language you know
• Pascals triangle code
• Memory allocations
• What new technologies you know
• About Cloud 
• Example of cloud

54) Branch - EEE

• Self introduction
• Basic questions on IOT (project was based on IoT)
• Language known? - C
• Many questions from c programming
• Code on Factorial of a number 
• In what technologies you would like to work in digital and why 

Check out this post for more interview questions and the general pattern of TCS DCA 2021.