backend-inteview-problems

I have created this so that you can find all backend interview preparation material at one place.

Design Pattern - https://sourcemaking.com/

Company Wise Quesions for Backend Developer

PhonePe

1. Graph is a linked list or not.
2. Design Inventory Management.
3. Topological sorting mini splitwise.
4. Desing short url
5. We have two city, if profits are written on daily basis , cost A->B or B->A = 20 Maxmie the profile ,seller can start from any city and can travel to any city to maximize profit.
6. KMP algorithm
7. B trees insertion and deletion

Cisco

1. Basic Computer Networking Questions.
2. How DNS works Data Structures.
3. Find the number of squares in a chess board.
4. Core java Algorithms average. 5 System design easy Implement LRU cache in constant time.

Adobe

1. Design a system that does image processing on a server and interfaces with a mobile phone.
2. Design a sorting algo which can take any type of input.
3. Find subarray with max product in an array of integers.
4. Implement Producer/Consumer in java.
5. Find the all the nodes in a tree which the distance of k to the target node.

Apple

1. When would you use a linked list vs. arraylist?
2. Validate binary search tree Merge two sorted lists.
3. Design bookshelf checkout class model.
4. Design Lyft.
5. Minimum path sum Given an array of positive integers is there a subarray of sum k.

Facebook

1. System design - text completion system for an edit text.
2. Serialize and deserialize binary tree.
3. Find all anagrams in a string.

Amazon

1. Word ladder Playing scrabble and you have N letters. Find word with max points.
2. Find mean from input stream.
3. Design air traffic control.

Uber

1. Shortest word distance Subarray sum equals K.
2. Design Uber eats.
3. Design a Elevator system.

Microsoft

1. Implement strStr().
2. Reverse words in a string clone linked list with a random pointer.
3. serialize and deserialize a binary tree.
4. Design a chess game.
5. Design a calendar.

Dropbox

1. Multiply strings Binary tree right side view.
2. Design logging system where Dropbox teams can use to log events

ZoloStays

1. Snake and ladder game.
2. You have a number, You have find out the subsets of 3,7 ,21 with summation that number with the subsets

Morgan Stanle / Wissen

1. Relaese and acuire method implementation.
2. How to override toString method of Integer.
3. class Max multiply in the array.
4. Lru.
5. Singleton class.
6. Multithreading synchronize.
7. Volatile
8. Vertical sum of binary tree.
9. How to sort array 0, 1,2 in array.
10. SOLID OF OPPS.
11. Book my show design.
12. Delete two adjacent character in strings.
13. How to check that pallindrome is possible or not.
14. How to sort hashmap with values not key.
15. Max multiplication of two numbers in array.
16. Volatile Transient.
17. Sort map based on values.
18. Factory design pattern.
19. Producer consumer problem 20.Show repeat number and its frequency

Yodlee Couting

1. Sort Radix Sort
2. Egg droping problem - Binary Search

Manthattan

1. Serialized class.
2. Find out total salary by department in which department no of employees count >2. Both department and employee table are different. 3.Find employee name and their respective manager from the same table.

NextGen

1. Object class and its method.
2. Various joins in sql.
3. Collections in java.
4. 3l 5 l bucket used to fill 4l.
5. Third most income employee name from employee table.
6. Difference between truncate and delete

Mindtree

1. Override in deep Shallow and deep cloning.
2. JVM Architecture.
3. String Pool.
4. Deadlock.
5. Static class.
6. Inner class.
7. Local Anonymous class.

Dassault System

Java - Everything Puzzle - 20 box having 20 apples 2 Ropes - how to find 15 min 5 and 7 litre bucket

kpmg

1. tic tac toe game design 4digit.
2. find max time, 4 digits are given.

Sigmoid

1. Level order traversal.
2. Min coin change problem.
3. is it bst maximum.
4. Sum of non consecutive number in array.
5. LCA in bst and normal tree

centurylink

1. Imlementation own hashcode for class.
2. Usecase for arraylist and linkedlist.
3. Can we write code to handle error create our own exception.
4. Why we create own exception.
5. Spring mvc in details.
6. Difference between rest controller and controller.

Oyo

1. Find the max number formed with no in array.
2. Number of ways can message can decode A -1 , B-2 12 can be AB and L as well so 2 ways

Paytm

1. Arrange the aaray like odd at odd places and even at even places.
2. Check if any sub array is present having sum equals to 0.
3. Singleton class with multi threading. Clone.
4. Design twitter.

Hashedin

1. Design lift.
2. Min Everytime with stack.
3. Reverse linked list.
4. Pairs having sum equals to zero.

MiQ

1. Minimum swap to arrange all 1s and 0s together Eg 11100001 => 11110000

Lenskart

1. Four operations , select copy paste , print max 9
2. Maximum water in 3002004.
3. Maze to reach end.
4. Cousins of a node in binary tree.

GoldmanSach

1. How to know number is power of 2 or not.
2. Dotproduct.
3. There is a addressbook contains first name, last name and address, another phone book contains first name, last name and phone. We need to find all the names who have address but don't have phone.
4. Max stock price between given interval of time. It may be of 10 second gap or 1 hour gap.
5. Find all the 1 rankers in all the classes from first to twelve from the database of school students. Test cases for Singleton class.

Amazon

1. Rotation of array.
2. Find numbers of pairs having difference equals to k.
3. Max area of island.
4. Print all the boundary nodes of binary tree.
5. Median of numbers as steram.
6. We have linkedlist like this 1->2->3->4->5 : Need to print like 1->5->2->4->3
7. Local Maxima.