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Fiserv Full Stack Developer Interview Questions and Answers

Updated 10 Jun 2024

Fiserv Full Stack Developer Interview Experiences

1 interview found

Interview experience
3
Average
Difficulty level
-
Process Duration
-
Result
-
Round 1 - One-on-one 

(2 Questions)

  • Q1. What are the java 1.8 features?
  • Ans. 

    Java 1.8 introduced several new features including lambda expressions, functional interfaces, streams, and default methods.

    • Lambda expressions allow you to write code in a more concise and readable way.

    • Functional interfaces are interfaces with a single abstract method, used for lambda expressions.

    • Streams provide a way to work with sequences of elements and perform operations on them.

    • Default methods allow interfaces to h...

  • Answered by AI
  • Q2. Write program to print element sorting by using java 8 feature.
  • Ans. 

    Program to print elements sorted using Java 8 features

    • Use Stream API to sort the elements

    • Use lambda expressions for sorting

    • Use the sorted() method to sort the elements

  • Answered by AI

Skills evaluated in this interview

Interview questions from similar companies

Interview experience
1
Bad
Difficulty level
Easy
Process Duration
Less than 2 weeks
Result
No response

I applied via Approached by Company and was interviewed in Sep 2024. There was 1 interview round.

Round 1 - Technical 

(2 Questions)

  • Q1. Sal queries simeple data structure question finding largest number in am array.
  • Q2. Solid principal

Interview Preparation Tips

Interview preparation tips for other job seekers - Simply waste of time they asked me 3-4 questions and didn't responded .
Interview experience
3
Average
Difficulty level
-
Process Duration
-
Result
-
Round 1 - Aptitude Test 

It will be a basic maths questions.

Round 2 - Group Discussion 

As a general topic of trend in world.

Round 3 - Coding Test 

To be known for programming knowledge about us.

Round 4 - Technical 

(2 Questions)

  • Q1. Programming oridanited
  • Q2. Skill knowledge questions
Round 5 - HR 

(2 Questions)

  • Q1. Tell me about your self.
  • Q2. Family background .

Interview Preparation Tips

Interview preparation tips for other job seekers - pls don't stress the candidate to suffer as high .
Interview experience
3
Average
Difficulty level
-
Process Duration
-
Result
-
Round 1 - Resume Shortlist 
Pro Tip by AmbitionBox:
Keep your resume crisp and to the point. A recruiter looks at your resume for an average of 6 seconds, make sure to leave the best impression.
View all tips
Round 2 - One-on-one 

(2 Questions)

  • Q1. What is react and why are we using it
  • Ans. 

    React is a JavaScript library for building user interfaces.

    • React allows for building reusable UI components

    • It uses a virtual DOM for efficient updates

    • React is declarative, making it easier to reason about code

    • It is widely used in web development for its performance and flexibility

  • Answered by AI
  • Q2. What is redux in react
  • Ans. 

    Redux is a predictable state container for JavaScript apps.

    • Redux is a state management library for React

    • It helps in managing the state of the application in a predictable manner

    • It follows a unidirectional data flow pattern

    • It has three main components: store, actions, and reducers

    • Store holds the state of the application

    • Actions are plain JavaScript objects that describe what happened

    • Reducers specify how the application's...

  • Answered by AI
Round 3 - Assignment 

Create a react app with redux

Interview Preparation Tips

Interview preparation tips for other job seekers - Just stay put and don't panic. So basically there are 10 people taking my interview at the same time which is too much but you have to find a way to stay calm

Skills evaluated in this interview

I was interviewed in Aug 2021.

Round 1 - Coding Test 

(2 Questions)

Round duration - 70 minutes
Round difficulty - Medium

There were 3 problems 1 was easy and 2 were of medium types.

  • Q1. Odd even level

    Given a binary tree. Find and return the modulus of the difference between the sum of odd level nodes and the sum of even level nodes.

    Input format:
    The first line contains an integer '...
  • Ans. DFS
    1. Create two variables, one for storing the sum of nodes at the odd level and one for storing the sum of nodes at even level.
    2. Use the below algorithm to calculate level sums where:

    oddSum: denotes sum of nodes at odd levels, initially 0.

    evenSum: denotes sum of nodes at ecen levels, initially 0.

    level: the level of the current node, initially 1. 

    void oddEvenLevelHelper(current, oddSum, evenSum, level)

     

    • If the cur...
  • Answered by CodingNinjas
  • Q2. Rotting Oranges

    You have been given a grid containing some oranges. Each cell of this grid has one of the three integers values:

  • Value 0 - representing an empty cell.
  • Value 1 - representing a fresh...
  • Ans. Naïve Solution

    The idea is very simple and naive. We will process the rotten oranges second by second. Each second, we rot all the fresh oranges that are adjacent to the already rotten oranges. The time by which there are no rotten oranges left to process will be our minimum time.

     

    In the first traversal of the grid, we will process all the cells with value 2 (rotten oranges). We will also mark their adjacent cells ...

  • Answered by CodingNinjas
Round 2 - Video Call 

(1 Question)

Round duration - 50 minutes
Round difficulty - Medium

the interviewer was very polite and straightforward, he didn't ask me to introduce myself and he directly jumps to the coding problems.
What is new about the relationship between the and tags in HTML5?
Explain Components, Modules and Services in Angular

  • Q1. Circular Move

    You have a robot currently standing at the origin (0, 0) of a two-dimensional grid and facing north direction. You are given a sequence of moves for the robot in the form of a string of size...

  • Ans. Optimal Approach

    Initialize a variable ‘direction’ with 0 which means that the robot is initially facing towards the north.

    direction: 0 -> Robot is facing towards the North
    direction: 1 -> Robot is facing towards the West 
    direction: 2 -> Robot is facing towards the South 
    direction: 3 -> Robot is facing towards the West

     

    Initialize two variables ‘x’ and ‘y’ as 0. They will represent the position ...

  • Answered by CodingNinjas
Round 3 - Video Call 

(2 Questions)

Round duration - 70 minutes
Round difficulty - Easy

What is a View in sql? What are the TRUNCATE, DELETE and DROP statements?

  • Q1. Rotate matrix by 90 degrees

    You are given a square matrix of non-negative integers 'MATRIX'. Your task is to rotate that array by 90 degrees in an anti-clockwise direction using constant extra spac...

  • Ans. Transpose and Reverse

    The idea is to find the transpose of the given matrix and then reverse the columns of the transposed matrix. For example:

    For the given 2D matrix:
    	[ [ 1,  2,  3 ],
    	  [ 4,  5,  6 ],
    	  [ 7,  8,  9 ] ]
    After taking transpose, it will become:
    	[ [ 1,  4,  7 ],
    	  [ 2,  5,  8 ],
    	  [ 3,  6,  9 ] ]
    After reversing the columns, it will ...
  • Answered by CodingNinjas
  • Q2. Minimum Characters For Palindrome

    Given a string STR of length N. The task is to return the count of minimum characters to be added at front to make the string a palindrome.

    For example, for the given st...

  • Ans. Brute Force
    • The idea is pretty simple, as we can add only at the front, thus, we need to work on the prefix of the string.
    • We need to find the largest prefix that is a palindrome. For example, in case of “abbac”, the largest prefix that is a palindrome is “abba”, now all you need to do is add the reverse of left out suffix i.e. “ca” at the front to make it a palindrome.
    • This can be done in the following way:-
      • Until the str...
  • Answered by CodingNinjas
Round 4 - HR 

(1 Question)

Round duration - 20 minutes
Round difficulty - Easy

  • Q1. Basic HR Questions

    Tell me about yourself?
    What do you know about Paytm?
    What are your strength and weaknesses?
    Job location preference?

Interview Preparation Tips

Professional and academic backgroundI completed Computer Science Engineering from Indian Institute Of Information Technology Sonepat. Eligibility criteria7 CGPA with no ongoing backlogs.Paytm (One97 Communications Limited) interview preparation:Topics to prepare for the interview - Data Structures and Algorithms, DBMS, Operating Systems, Computer Networking, System Design.Time required to prepare for the interview - 6 monthsInterview preparation tips for other job seekers

Tip 1 : Deep knowledge of the projects mentioned in your resume is a must.
Tip 2 : Practice as many problems as you can from leetcode.

Application resume tips for other job seekers

Tip 1 : mention 1 or 2 projects in your resume.
Tip 2 : don't put false things in your resume.

Final outcome of the interviewSelected

Skills evaluated in this interview

I was interviewed in Jul 2021.

Round 1 - Coding Test 

(2 Questions)

Round duration - 120 Minutes
Round difficulty - Medium

This was a coding round conducted from 12 PM to 2 PM and it was not proctored but we could not switch the tabs. There were 2 coding questions each of 100 marks. The MCQ had HTML,CSS, JS, SQL, Coding and aptitutude questions.

  • Q1. N Queens

    You are given an integer 'N'. For a given 'N' x 'N' chessboard, find a way to place 'N' queens such that no queen can attack any other queen on the chessboard.

    A ...

  • Ans. Backtracking
    1. Instead of checking all the places on the chessboard, we can use backtracking and place queen row-wise or column-wise.
    2. Suppose we place queens row-wise, and we start with the very first row. Place the queen and move to the next row until either there is a solution or there are no viable cells left.
    3. As we backtrack, check to place the queen in the different columns of the same row.
    4. When we can place a queen at ...
  • Answered by CodingNinjas
  • Q2. Rearrange String

    You are given a string “S”. Your task is to rearrange the characters of a string “S”, such that it does not contain any two adjacent characters which are the same.

    If it is possible to r...

  • Ans. Brute force

    In this approach, we will generate all the possible rearrangements of the string and check if the current string in our rearrangement does not have any two adjacent characters that are the same. If we can find any string which satisfies our criteria then we will return that string else we will return “not possible”.

     

    We can implement the above approach by – 

    1. Generate all permutations of a string.
    2. For ...
  • Answered by CodingNinjas
Round 2 - Video Call 

(2 Questions)

Round duration - 60 minutes
Round difficulty - Easy

There were two interviewers. They started by asking me to introduce myself and asked me to explain any one of my projects in my resume and after that, they asked me about the ML algorithms used in my project and about the difficulties faced. What is NaN property in JavaScript? This took around 10 minutes. They also asked 2 coding questions.
It was conducted at 10 AM on CodePair and MS Teams. Interviewers were friendly.

  • Q1. Group Anagrams Together

    You have been given an array/list of strings 'STR_LIST'. You are supposed to return the strings as groups of anagrams such that strings belonging to a particular group are a...

  • Ans. Sorting based Approach

    The idea behind this approach is that two or more than two strings are anagrams if and only if their sorted strings are equal. So we will use a HashMap, let’s say “anagramGroup”, where each key is a sorted string, and the key will be mapping to the list of indices from the given list of strings that form a group of anagrams. This means that if we sort the strings at those indices, we will get the ...

  • Answered by CodingNinjas
  • Q2. Friends Pairing Problem

    You are given an integer ‘N’, which denotes there are ‘N’ friends. You are supposed to form some pairs them satisfying the following conditions:

    1. Each friend can be paired with ...

  • Ans. Bruteforce

    The idea is to solve the problem using recursion and break down the problem into different subproblems.

    Let’s define NUMBER_OF_WAYS(N) as the total number of ways ‘N’ friends can be paired up or remain single.

    The N-th person has two choices - either remain single or pair up with one of the other ‘N - 1’ friends.

    If he remains single, then the number of possible pairings are NUMBER_OF_WAYS(N - 1) as there are (N...

  • Answered by CodingNinjas
Round 3 - Video Call 

(2 Questions)

Round duration - 60 Minutes
Round difficulty - Medium

There were 2 questions based on data structures, the round started from 1.15 PM .Some SQL questions like What is a Subquery? What are its types? What are UNION, MINUS and INTERSECT commands?

  • Q1. Vertical Order Traversal

    The Ultimate Ninja Ankush is a straightforward, no-nonsense guy and loves binary Trees, and he has given you a binary tree, and you have to return the vertical order traversal of t...

  • Ans. Efficient Approach

    The intuition is to find the breadth of the tree first so that we can beforehand know the maximum horizontal distance and minimum horizontal distance of a node from the root node. We can use the absolute value of minimum horizontal distance as an offset. Now we can use an array/list visited to store the visited nodes where ith element will store the node at (i - offset”) distance horizontally from the...

  • Answered by CodingNinjas
  • Q2. Divide Two Integers

    You are given two integers ‘dividend’ and ‘divisor’. You are required is to divide the integers without using multiplication, division and modular operators. Your task is to return the ...

  • Ans. Using Subtraction

    We can subtract the divisor from the dividend until the dividend is greater than the divisor. The quotient will be equal to the number of total subtractions performed.

     

    Below is the detailed algorithm:

     

    1. Store the ‘IS_DIVIDEND_NEGATIVE = false’ and ‘IS_DIVISOR_NEGATIVE = false’.
    2. Check if the ‘DIVIDEND’ and ‘DIVISOR’ are positive or negative and update the values of ‘IS_DIVIDEND_NEGATIVE’ and ...
  • Answered by CodingNinjas
Round 4 - HR 

(1 Question)

Round duration - 30 Minutes
Round difficulty - Easy

The round was at 7.30 PM and I was asked to introduce myself and we had basic talk on where I live and my interests. I asked about the work culture and about the role at the end.

  • Q1. Puzzle

    He showed a puzzle where n-balloons were there and I had to burst maximum balloons using an arrow.

  • Ans. 

    This was basically finding a maximum number of points in a line. I coded that but he wanted an improved solution. He told me to assume the positions of balloons in a matrix where 1 represents if the balloon is present and vice versa. Then I had to find which row or column or diagonal had the maximum number of 1’s. Later he asked me if I had some questions.

  • Answered by CodingNinjas

Interview Preparation Tips

Professional and academic backgroundI completed Computer Science Engineering from VIT University. I applied for the job as Fullstack Developer in ChennaiEligibility criteriaPercentage Criteria in X and XII: 85% or 8.5 CGPA, Pursuing Degree: 85% or 8.5 CGPA, No Standing ArrearsPaypal interview preparation:Topics to prepare for the interview - Trees, Graphs, Dynamic Programming, Arrays, StacksTime required to prepare for the interview - 6 monthsInterview preparation tips for other job seekers

Tip 1 : Practice atleast 400 questions of leetcode topics wise.
Tip 2 : Participate in hackathons.
Tip 3 : Have 2 good projects atleast and be very good in project concepts.

Application resume tips for other job seekers

Tip 1 : Have good projects in your resume and have clear idea of what you have done in those.
Tip 2 : Mention languages, frameworks, subjects only when you have proper hold on them, don't mention things you don't know properly.

Final outcome of the interviewSelected

Skills evaluated in this interview

I applied via Campus Placement

Round 1 - Resume Shortlist 
Pro Tip by AmbitionBox:
Don’t add your photo or details such as gender, age, and address in your resume. These details do not add any value.
View all tips
Round 2 - Coding Test 

3 coding questions

Interview Preparation Tips

Interview preparation tips for other job seekers - Prepare well brush up your coding skills.

I was interviewed in Aug 2021.

Round 1 - Coding Test 

(3 Questions)

Round duration - 70 minutes
Round difficulty - Medium

The test started around 3 pm and was of 70 minutes. 3 coding questions were asked which were mainly on trees and number theory.

  • Q1. Factorial of a Number

    Write a program to find the factorial of a number.

    Factorial of n is:

    n! = n * (n-1) * (n-2) * (n-3)....* 1

    Output the factorial of 'n'. If it does not exist, output ...

  • Ans. Using while() loop
    • This can be done using an if-else-if ladder to check for negative,0, and positive numbers.
    • If the input is a positive number use a while loop to multiply n with n-1, n-2…1 and get the desired output.
    Space Complexity: O(1)Explanation: Time Complexity: O(1)Explanation:
  • Answered by CodingNinjas
  • Q2. Next Greater Element

    For a given array/list of integers of size N, print the Next Greater Element(NGE) for every element. The Next Greater Element for an element X is the first element on the right side of...

  • Ans. Brute Force

    For every element in the array, we will run a loop on its right side. As soon as we find an element on its right side which is greater than it, we will break the loop, assign it as the NGE of this element, move forward, and do the same for the next element.

    Space Complexity: O(1)Explanation:

    O(1)

     

    No extra space is used.

    Time Complexity: O(n^2)Explanation:

    O(N ^ 2),  Where N is the number of elements ...

  • Answered by CodingNinjas
  • Q3. Ceil from BST

    Ninja is given a binary search tree and an integer. Now he is given a particular key in the tree and returns its ceil value. Can you help Ninja solve the problem?

    Note:
    Ceil of an integer i...
  • Ans. Brute Force

    We will traverse the Binary search tree from the root node till we find the node whose key value is given, and upon getting that, we return the ceil value of it.


     

    The steps are as follows:  

    • Initialize ‘ceilValue’ to store the ceil value to be returned.
    • We run a while loop till the value of the node is not equal to NULL.
      • If the value of the node is equal to ‘X’’ then we return the node value.
      • If th...

  • Answered by CodingNinjas
Round 2 - Video Call 

(2 Questions)

Round duration - 60 minutes
Round difficulty - Medium

Interviewer was very friendly and supportive. My interview happened on google meet. What is a View? What is Denormalization? Difference between “==” and “===” operators in js.

  • Q1. Sub Sort

    You are given an integer array ‘ARR’. You have to find the length of the shortest contiguous subarray such that, if you sort this subarray in ascending order, then the whole array will be sorted i...

  • Ans. Brute Force

    In this approach, we consider every possible subarray that can be formed from the given array ‘ARR’. For every subarray ARR[i … j] considered, we need to check whether this is the smallest unsorted subarray or not.

     

    The algorithm is as follows:

    1. Let’s take the variable ‘ANS’ equal to 'N' (the length of the array) initially.
    2. Now for every subarray ARR[i … j], we will find the maximum and minimum value lying ...
  • Answered by CodingNinjas
  • Q2. Sort 0 1 2

    You have been given an integer array/list(ARR) of size 'N'. It only contains 0s, 1s and 2s. Write a solution to sort this array/list.

    Note :
    Try to solve the problem in 'Single Sca...
  • Ans. Sorting

    Use any good sorting algorithm like Merge Sort, Quick Sort or inbuilt sorting function of different languages.

    • Sort the Array and just return.
    Space Complexity: O(1)Explanation:

    O(1), As we are using constant space.

    Time Complexity: O(nlogn)Explanation:

    O(N*log(N)), where ‘N’ is the size of the array.

    We are using inbuilt sort algorithm which has Overall Time Complexity O(N*log(N))

  • Answered by CodingNinjas
Round 3 - Video Call 

(2 Questions)

Round duration - 60 minutes
Round difficulty - Medium

What are some of the advantages of Angular over other frameworks?

  • Q1. Check If Two Nodes Are Cousins

    You are given an arbitrary binary tree consisting of N nodes, where each node is associated with a certain value, and two node values, a and b, you need to check if these no...

  • Ans. Recursive Solution
    • Find the levels of both the given nodes.
    • This can be done by making a separate function for finding the level/by using level order traversal.
    • The levels should be the same.
    • Check if both the nodes are siblings or not.
    • This can again be done by simply going through the entire Binary Tree and checking if the node’s children are the given two nodes. If this is true, then given two nodes are siblings and henc...
  • Answered by CodingNinjas
  • Q2. OS Questions

    What is spooling?
    What are the conditions for deadlock to occur?

Round 4 - HR 

(3 Questions)

Round duration - 10 minutes
Round difficulty - Easy

I got a call from HR in the evening around 6:30 pm.

  • Q1. Basic HR Question

    Tell me about yourself?

  • Ans. 

    Tip 1 : Do prepare such questions before hand only.
    Tip 2 : Speak confidently.

  • Answered by CodingNinjas
  • Q2. Basic HR Question

    How was your experience with previous two tech rounds?

  • Ans. 

    Tip 1 : Do remember the names of the interviewers who took your interview.

  • Answered by CodingNinjas
  • Q3. Basic HR Question

    What do you know about Paytm?

  • Ans. 

    Tip 1 : Do a research before hand about what does the company do.

  • Answered by CodingNinjas

Interview Preparation Tips

Professional and academic backgroundI completed Computer Science Engineering from TIET - Thapar Institute of Engineering And Technology. Eligibility criteriaAbove 7 CGPAPaytm (One97 Communications Limited) interview preparation:Topics to prepare for the interview - Data Structures and Algorithms, OOPS, OS, DBMS, Computer Networks, System DesignTime required to prepare for the interview - 7 monthsInterview preparation tips for other job seekers

Tip 1 : Practice at least 350 questions to have good hold on data structures
Tip 2 : Practice at least 100 - 150 company specific coding questions.
Tip 3 : Try to give timing contests to build up your speed.

Application resume tips for other job seekers

Tip 1 : Keep your resume only of 1 page
Tip 2 : Showcase your major projects on the top

Final outcome of the interviewSelected

Skills evaluated in this interview

I was interviewed before Mar 2021.

Round 1 - Coding Test 

(2 Questions)

Round duration - 70 minutes
Round difficulty - Easy

there was some coding questions and some mcqs related to js, html, css, java and aptitude.

  • Q1. Bridges In A Graph

    Given an undirected graph of V vertices and E edges. Your task is to find all the bridges in the given undirected graph. A bridge in any graph is defined as an edge which, when removed, ...

  • Ans. Brute Force

    The brute force approach to find all the bridges in a given graph is to check for every edge if it is a bridge or not, by first not considering current edge is not in given graph and then checking if the vertices that it was connecting are still connected or not, using DFS(DepthFirst Search). Given below is an algorithm that will find all bridges in a graph.

     

    Algorithm :

    1. Initialise a visited array with fa...
  • Answered by CodingNinjas
  • Q2. House Robber

    Mr. X is a professional robber planning to rob houses along a street. Each house has a certain amount of money hidden. All houses along this street are arranged in a circle. That means the fir...

  • Ans. 

    The task is to find the maximum amount of money Mr. X can rob from houses arranged in a circle without alerting the police.

    • The problem can be solved using dynamic programming.

    • Create two arrays to store the maximum amount of money robbed when considering the first house and when not considering the first house.

    • Iterate through the array and update the maximum amount of money robbed at each house.

    • The final answer will be

  • Answered by AI

Interview Preparation Tips

Professional and academic backgroundI completed Electrical Engineering from Indian Institute of Technology (Indian School of Mines), Dhanbad. I applied for the job as Fullstack Developer in NoidaEligibility criteria7 CGPAPaytm (One97 Communications Limited) interview preparation:Topics to prepare for the interview - coding practice, Operating system , OOPs, Dbms , projects .Time required to prepare for the interview - 4 monthsInterview preparation tips for other job seekers

Tip 1 : Do 300+ questions on IB or leetcode or gfg 
Tip 2 : Must do DSA course of coding ninjas for clear understanding
Tip 3 : Must complete CS subjects also

Application resume tips for other job seekers

Tip 1 : not add too much things
Tip 2 : be confident that you write in CV

Final outcome of the interviewRejected

I was interviewed before Mar 2021.

Round 1 - Coding Test 

(3 Questions)

Round duration - 90 minutes
Round difficulty - Medium

It was in the evening, at around 3 - 4 PM. There were 3 coding questions. One easy, two moderate ones. The platform had autocomplete feature too.

  • Q1. Parity Move

    Ninja recently studied odd and even numbers but he is more interested in even numbers.

    He has an array ‘A’ containing ‘N’ integers. He will transform this array by moving all the even numbers...

  • Ans. Sorting Approach

     

    Approach : 

     

    • Implement a comparator that check numbers ‘a’ and ‘b’ :
    • If both are even or both are odd, it can return any priority between them as we need to sort by parity here.
    • If one of them is even and the other is odd, prioritize even numbers to order them first.


     

    Algorithm : 
     

    • Call the comparator function on array ‘A’ that prioritizes the least among two integers ‘a%2’ and...

  • Answered by CodingNinjas
  • Q2. Anagram Pairs

    Pre-requisites: Anagrams are defined as words or names that can be formed by rearranging letters of another word. Such as "spar" can be formed by rearranging letters of "rasp&q...

  • Ans. Count Characters

    Anagrams have a unique property: the counts of each distinct character present in both strings are the same. One way to check this is: 

    1. Sort both strings, so that all the same characters come together
    2. Then loop through both strings together and check each element in both strings one by one
    3. If at any position, the characters are found to be different or if the lengths of the two strings are different, ...
  • Answered by CodingNinjas
  • Q3. LCA In A BST

    You are given a binary search tree of integers with N nodes. You are also given references to two nodes P and Q from this BST.

    Your task is to find the lowest common ancestor(LCA) of these t...

  • Ans. Depth - First Traversal

    We will traverse the BST in a depth-first manner. The moment we encounter either of the nodes P or Q, we will return some boolean flag. The least common ancestor would then be the node for which both the subtree recursions return a ‘True’  flag value.   

     

    The algorithm will be -

    • We will start traversing a BST from the root node in a recursive manner.
    • Let the current node in each...
  • Answered by CodingNinjas
Round 2 - Video Call 

(3 Questions)

Round duration - 50 Minutes
Round difficulty - Medium

They asked 2 coding questions and 2 sql queries in this round

  • Q1. Longest Palindromic Substring

    Given a string ’S’ consisting of lower case English letters, you are supposed to return the longest palindromic substring of ‘S’.

    Note that in case of more than one longest ...

  • Ans. Brute Force

    The brute force solution is to pick all possible starting and ending positions for a substring and verify if it is a palindrome.

     

    The steps are as follows:

     

    1. If the length of the given string is zero, return an empty string. Else,
    2. Start checking each substring of the given string ‘S’ whether the substring is a palindrome or not.
    3. To do this first, run the two nested loops.
    4. These two loops pick up all the ...
  • Answered by CodingNinjas
  • Q2. Trapping Rain Water

    You have been given a long type array/list 'ARR' of size 'N'. It represents an elevation map wherein 'ARR[i]' denotes the elevation of the 'ith' bar. Pri...

  • Ans. Brute Force Approach

    The idea here is to travel over every elevation on the map and calculate the units of water the elevation can store.

     

    Here is the algorithm :

     

    1. Iterate over every elevation or element and find the maximum elevation on to the left and right of it. Say, the maximum elevation on to the left of the current elevation or element that we are looking at is ‘maxLeftHeight’ and the maximum elevation on...
  • Answered by CodingNinjas
  • Q3. SQL Question

    A nested SQL query

Round 3 - Video Call 

(2 Questions)

Round duration - 50 Minutes
Round difficulty - Medium

This round was about OS, networking and my projects. What are the different ways to style a React component?
Name a few techniques to optimize React app performance.

  • Q1. OS Questions

    Theory questions about OS . Multithreading, Scheduling Algorithms

  • Q2. Puzzle

    There are 12 coins. 11 of them have same weight and one is light in weight than others. We have a weighing balance. Find the minimum times we have to balance to find out the lighter one.

Round 4 - HR 

(1 Question)

Round duration - 30 Minutes
Round difficulty - Easy

It was a fun round, in which they ask about your preferences about programming languages, technologies or your hobbies. If you reach this round, it means that your chances of selection are 99%.

  • Q1. Basic HR Question

    What was the biggest hurdle you faced while developing a project

  • Ans. 

    Tip 1 : Be truthful, do build some projects on your own so that you can answer these kind of questions truthfully.
    Tip 2 : Be confident
    Tip 3 : Ask any questions you want to ask from the interviewer

  • Answered by CodingNinjas

Interview Preparation Tips

Professional and academic backgroundI applied for the job as Fullstack Developer in NoidaEligibility criteriaAbove 7 CGPAPaytm (One97 Communications Limited) interview preparation:Topics to prepare for the interview - Data structures, OOPS, Networking, Dynamic Programming, DBMS, JavascriptTime required to prepare for the interview - 6 monthsInterview preparation tips for other job seekers

Tip 1 : If weak in coding, enroll for Coding Ninjas eminence course
Tip 2 : Practice everyday, atleast 2- 3 questions
Tip 3 : Participate in weekly coding contests on leetcode

Application resume tips for other job seekers

Tip 1 : Keep in One page
Tip 2 : Don't mention your hobbies, recruiters are not interested in them and moreover hobbies take up space
Tip 3 : Have some unique projects on your resume. The projects should be self made, not from code-along sessions from youtube.

Final outcome of the interviewSelected

Skills evaluated in this interview

Fiserv Interview FAQs

How many rounds are there in Fiserv Full Stack Developer interview?
Fiserv interview process usually has 1 rounds. The most common rounds in the Fiserv interview process are One-on-one Round.
How to prepare for Fiserv Full Stack Developer interview?
Go through your CV in detail and study all the technologies mentioned in your CV. Prepare at least two technologies or languages in depth if you are appearing for a technical interview at Fiserv. The most common topics and skills that interviewers at Fiserv expect are Java, Angularjs, Full Stack, Bootstrap and CSS.
What are the top questions asked in Fiserv Full Stack Developer interview?

Some of the top questions asked at the Fiserv Full Stack Developer interview -

  1. Write program to print element sorting by using java 8 featu...read more
  2. What are the java 1.8 featur...read more

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