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Wissen Technology Java Developer Interview Questions, Process, and Tips

Updated 21 Jan 2025

Top Wissen Technology Java Developer Interview Questions and Answers

  • Q1. Parent class has run() and walk() . Parent run() - calls walk() Child Class overrides Parent class Inside run() - calls super.run() Walk() - calls super.walk In main clas ...read more
  • Q2. 2. What will happen if hashcode only returns a constant? How will it affect the internal working of the HashMap?
  • Q3. How to sort a list of students on the basis of their First name?
View all 53 questions

Wissen Technology Java Developer Interview Experiences

22 interviews found

Interview experience
5
Excellent
Difficulty level
Easy
Process Duration
-
Result
-

I was interviewed in Jul 2024.

Round 1 - Technical 

(2 Questions)

  • Q1. What is Kafka ?
  • Ans. 

    Kafka is a distributed streaming platform used for building real-time data pipelines and streaming applications.

    • Kafka is designed to handle high-throughput, fault-tolerant, and scalable real-time data streams.

    • It allows for the publishing and subscribing to streams of records, similar to a message queue.

    • Kafka is often used for log aggregation, stream processing, event sourcing, and real-time analytics.

    • It provides featur...

  • Answered by AI
  • Q2. What are JOINS in MySql
  • Ans. 

    JOINS in MySql are used to combine rows from two or more tables based on a related column between them.

    • JOINS are used to retrieve data from multiple tables based on a related column

    • Types of JOINS include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN

    • Example: SELECT * FROM table1 INNER JOIN table2 ON table1.column = table2.column

  • Answered by AI

Skills evaluated in this interview

Interview experience
2
Poor
Difficulty level
Moderate
Process Duration
2-4 weeks
Result
No response

I was interviewed in Apr 2024.

Round 1 - Technical 

(1 Question)

  • Q1. Java questions on multithreading, data structures, and algorithms
Round 2 - Technical 

(1 Question)

  • Q1. Puzzle questions, complete the code questions

Interview Preparation Tips

Interview preparation tips for other job seekers - They will waste your time

Java Developer Interview Questions Asked at Other Companies

asked in Deloitte
Q1. Sort 0 and 1 Problem Statement Given an integer array ARR of size ... read more
Q2. Parent class has run() and walk() . Parent run() - calls walk() C ... read more
asked in Infosys
Q3. Which should be preferred between String and StringBuffer when th ... read more
asked in Deloitte
Q4. Convert BST to Greater Sum Tree Given a Binary Search Tree (BST) ... read more
Q5. 2. What will happen if hashcode only returns a constant? How will ... read more
Interview experience
3
Average
Difficulty level
Moderate
Process Duration
2-4 weeks
Result
Not Selected

I applied via LinkedIn and was interviewed in Oct 2023. There were 3 interview rounds.

Round 1 - Aptitude Test 

1 hr. of the test, 10 questions on core Java concepts, 2 SQL queries, 2 coding question

Round 2 - One-on-one 

(4 Questions)

  • Q1. 2 coding questions, 1 SQL queries
  • Q2. Sorting in the string
  • Ans. 

    Sorting strings in an array

    • Use Arrays.sort() method to sort the array of strings

    • You can also use a custom Comparator to define the sorting criteria

    • Remember that sorting is case-sensitive by default

  • Answered by AI
  • Q3. Priority queue in the array
  • Ans. 

    Priority queue can be implemented using an array by maintaining the order of elements based on their priority.

    • Maintain the order of elements in the array based on their priority level.

    • When adding elements, insert them in the correct position to maintain the priority order.

    • When removing elements, remove the element with the highest priority first.

    • Example: ["High Priority", "Low Priority", "Medium Priority"]

  • Answered by AI
  • Q4. Left join on two table
Round 3 - One-on-one 

(2 Questions)

  • Q1. 1 coding question on the stack, this interviewer was not good, he did not show any attention in the interview.
  • Q2. 1 question on the stack

Interview Preparation Tips

Topics to prepare for Wissen Technology Java Developer interview:
  • Data Structures
  • Algorithms
  • oops
  • SQL
  • Core Java
Interview preparation tips for other job seekers - prepare moderate-level coding questions, prepare SQL queries very well

Skills evaluated in this interview

Interview experience
4
Good
Difficulty level
Moderate
Process Duration
Less than 2 weeks
Result
No response

I applied via Walk-in and was interviewed in Jul 2023. There were 4 interview rounds.

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 - Coding Test 

There is a hacker rank test for 60 minutes Link provided by the time of 1st round live screen share with hr taking screenshot for govt id proof.
Test has a 8 question in that 5 are mcqs and 2 are coding and 1 is SQL query.

Round 3 - One-on-one 

(1 Question)

  • Q1. F2F interview was there. Basic of Multithreading in java. Split array into chunks of given size. Class level and Object level synchronization. Given a nested array and make it into flatten array. {{1}, 2...
  • Ans. You can find all answers here -----
  • Answered Anonymously
Round 4 - One-on-one 

(8 Questions)

  • Q1. After this we have a 3rd F2F round- What is Multithreading in java?
  • Q2. Convert String camel case to snake case.
  • Ans. 

    Converts a camel case string to snake case.

    • Split the string by uppercase letters

    • Convert each word to lowercase

    • Join the words with underscores

  • Answered by AI
  • Q3. Write a Java program using multithreading to print below output: n=10 Thread-1 : 1 Thread-2 : 2 Thread-3 : 3 Thread-1 : 4 Thread-2 : 6 . . Thread-1 : 10
  • Ans. 

    A Java program using multithreading to print numbers from 1 to 10 in a specific pattern.

    • Create three threads and assign them to print numbers in a specific pattern

    • Use synchronization to ensure the correct order of printing

    • Use a loop to iterate from 1 to 10 and assign the numbers to the threads

    • Print the thread name and the assigned number in the desired format

  • Answered by AI
  • Q4. Suggestion on best way for Java collection to store csv data. and if needed any operation on how to do? there are millions of data need to store in java collection. and some validations on this.
  • Q5. How to detect a loop into LinkedList?
  • Ans. 

    To detect a loop in a LinkedList, we can use the Floyd's cycle-finding algorithm.

    • Initialize two pointers, slow and fast, both pointing to the head of the LinkedList.

    • Move slow pointer by one step and fast pointer by two steps at a time.

    • If there is a loop, the slow and fast pointers will eventually meet.

    • If either of the pointers reaches the end of the LinkedList, there is no loop.

  • Answered by AI
  • Q6. Difference between Callable and Runnable Class?
  • Ans. 

    Callable and Runnable are interfaces in Java used for concurrent programming. Callable returns a result and can throw an exception, while Runnable does not return a result or throw an exception.

    • Callable is a generic interface with a method called 'call()', while Runnable is a functional interface with a method called 'run()'.

    • Callable can return a result using the 'Future' interface, while Runnable cannot.

    • Callable can t...

  • Answered by AI
  • Q7. How to create Thread in Java and What are the ways?
  • Ans. 

    Threads in Java allow concurrent execution of multiple tasks. They can be created in multiple ways.

    • Using the Thread class

    • Implementing the Runnable interface

    • Using the Executor framework

    • Using the Callable interface with ExecutorService

  • Answered by AI
  • Q8. Write a SQL Query for having student table Name Subjects Marks Data like- abc Eng 19 abc Phy 17 abc Chem 20 xyz Eng 16 xyz Phy 18 xyz Chem 12 ..... output should be like a list display at the marks board ...

Interview Preparation Tips

Topics to prepare for Wissen Technology Java Developer interview:
  • Java Collections
  • Core Java
  • HashMap
  • Synchronization
  • Logic
  • Java Array
Interview preparation tips for other job seekers - Should have strong knowledge of multithreading and Java Collections.

Skills evaluated in this interview

Wissen Technology interview questions for designations

 Senior Java Developer

 (2)

 Java Software Developer

 (2)

 Software Developer

 (17)

 Angular Developer

 (2)

 Salesforce Developer

 (1)

 Application Developer

 (1)

 Senior Java Software Engineer

 (1)

 Senior Software Developer

 (4)

Interview experience
3
Average
Difficulty level
Hard
Process Duration
-
Result
Not Selected

I was interviewed in Apr 2024.

Round 1 - Coding Test 

It was on online platform consists of 7 questions, 2 coding each of 40 marks, 1 SQL query- 20 marks and 4 MCQ's 5 marks each

Round 2 - Technical 

(1 Question)

  • Q1. To merge the array and print it in sorted manner , time complexity of code what you have written, optimise it if required. More on Map, System design questions

Get interview-ready with Top Wissen Technology Interview Questions

Interview experience
5
Excellent
Difficulty level
Moderate
Process Duration
Less than 2 weeks
Result
Not Selected

I applied via Campus Placement and was interviewed in Jan 2024. There were 3 interview rounds.

Round 1 - Coding Test 

3 coding ques , basics of oops

Round 2 - Coding Test 

3 coding ques , basics of oops

Round 3 - Technical 

(1 Question)

  • Q1. What are the ways to create the threads and all
  • Ans. 

    There are two ways to create threads in Java: by extending the Thread class or by implementing the Runnable interface.

    • Extending the Thread class: Create a new class that extends the Thread class and override the run() method.

    • Implementing the Runnable interface: Create a new class that implements the Runnable interface and implement the run() method.

    • Example using Thread class: MyThread extends Thread { public void run()...

  • Answered by AI

Interview Preparation Tips

Interview preparation tips for other job seekers - just focus on DSA

Skills evaluated in this interview

Java Developer Jobs at Wissen Technology

View all
Interview experience
5
Excellent
Difficulty level
Easy
Process Duration
Less than 2 weeks
Result
Selected Selected

I applied via Naukri.com and was interviewed in Feb 2023. There were 3 interview rounds.

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 

(18 Questions)

  • Q1. 1. Can we keep an object of a Class as key in HashMap?
  • Ans. 

    Yes, we can keep an object of a Class as a key in HashMap.

    • The key in a HashMap can be any non-null object.

    • The key's class must override the hashCode() and equals() methods for proper functioning.

    • If two objects have the same hashCode(), they will be stored in the same bucket and compared using equals().

    • If the key is mutable, its state should not be modified after it is used as a key in the HashMap.

  • Answered by AI
  • Q2. 2. What will happen if hashcode only returns a constant? How will it affect the internal working of the HashMap?
  • Ans. 

    If hashcode returns a constant, all elements will be stored in the same bucket, resulting in poor performance.

    • All elements will be stored in the same bucket of the HashMap.

    • This will lead to poor performance as the HashMap will essentially become a linked list.

    • Retrieving elements will take longer as the HashMap will have to iterate through the linked list to find the desired element.

  • Answered by AI
  • Q3. 3. What if we do not override Equals method ? What is we do not override Hashcode method?
  • Ans. 

    Not overriding equals method can lead to incorrect comparison of objects. Not overriding hashCode method can lead to incorrect behavior in hash-based data structures.

    • If equals method is not overridden, the default implementation from Object class will be used which compares object references.

    • This can lead to incorrect comparison of objects where two different objects with same content are considered unequal.

    • If hashCode...

  • Answered by AI
  • Q4. 4. How to make a class immutable?
  • Ans. 

    To make a class immutable, we need to ensure that its state cannot be modified after creation.

    • Make all fields private and final

    • Do not provide any setters

    • Ensure that mutable objects are not returned from methods

    • Make the class final or use a private constructor

    • Consider using defensive copying

  • Answered by AI
  • Q5. 5. If we have a mutable object inside immutable class then how will you handle it?
  • Ans. 

    To handle a mutable object inside an immutable class, make the object private and provide only read-only access methods.

    • Make the mutable object private to encapsulate it within the immutable class.

    • Provide read-only access methods to retrieve the state of the mutable object.

    • Ensure that the mutable object cannot be modified from outside the class.

    • If necessary, create defensive copies of the mutable object to prevent unin

  • Answered by AI
  • Q6. 6. Advantages and Disadvantages of immutable class?
  • Ans. 

    Immutable classes have advantages like thread safety, security, and simplicity, but also have disadvantages like memory usage and performance overhead.

    • Advantages of immutable classes:

    • - Thread safety: Immutable objects can be safely shared among multiple threads without the need for synchronization.

    • - Security: Immutable objects cannot be modified, which can prevent unauthorized changes to sensitive data.

    • - Simplicity: Im...

  • Answered by AI
  • Q7. How to sort a list of students on the basis of their First name?
  • Ans. 

    To sort a list of students on the basis of their First name, use the Collections.sort() method with a custom Comparator.

    • Create a custom Comparator that compares the first names of the students.

    • Implement the compare() method in the Comparator to compare the first names.

    • Use the Collections.sort() method to sort the list of students using the custom Comparator.

  • Answered by AI
  • Q8. Object level Lock vs Class level lock?
  • Ans. 

    Object level lock is used to synchronize access to an instance method or block, while class level lock is used to synchronize access to a static method or block.

    • Object level lock is acquired on a per-object basis, while class level lock is acquired on a per-class basis.

    • Object level lock is useful when multiple threads are accessing the same instance method or block, while class level lock is useful when multiple thread...

  • Answered by AI
  • Q9. If there is a class inside it we have a method - public void synchronized M1() - inside method - Thread.Sleep(500); We create 2 different object of the class and invoke the method. Ob1.M1() Ob2.M1() How ...
  • Q10. Using Java 8 find the sum of squares of all the odd numbers in the arraylist.
  • Ans. 

    Using Java 8, find the sum of squares of all the odd numbers in the arraylist.

    • Use the stream() method to convert the ArrayList to a stream

    • Use the filter() method to filter out the even numbers

    • Use the mapToInt() method to square each odd number

    • Use the sum() method to find the sum of the squared odd numbers

  • Answered by AI
  • Q11. LeetCode 1 - Two Sum.
  • Q12. LeetCode 20 - Valid Parantheses
  • Q13. Parent class has run() and walk() . Parent run() - calls walk() Child Class overrides Parent class Inside run() - calls super.run() Walk() - calls super.walk In main class Parent p = new child() p.ru...
  • Ans. 

    The order of execution will be: parent's run() -> child's run() -> parent's walk()

    • When p.run() is called, it will first execute the run() method of the parent class

    • Inside the parent's run() method, it will call the walk() method of the parent class

    • Since the child class overrides the parent class, the child's run() method will be executed next

    • Inside the child's run() method, it will call the run() method of the parent c...

  • Answered by AI
  • Q14. LeetCode - 532 , K diff pairs
  • Q15. What is Serialization?
  • Ans. 

    Serialization is the process of converting an object into a stream of bytes to store or transmit it over a network.

    • Serialization is used to save the state of an object and recreate it later.

    • It is also used to send objects over a network as a byte stream.

    • Java provides Serializable interface to implement serialization.

    • Serialization can be used for deep cloning of objects.

    • Example: Saving an object to a file or sending it

  • Answered by AI
  • Q16. Synchronized Map vs Concurrent hashmap
  • Ans. 

    Synchronized Map is thread-safe but slower, while Concurrent HashMap is faster but not entirely thread-safe.

    • Synchronized Map locks the entire map during write operations, causing other threads to wait.

    • Concurrent HashMap allows multiple threads to read and write simultaneously, using a lock-free approach.

    • Synchronized Map is useful for small maps or low-concurrency scenarios.

    • Concurrent HashMap is better suited for large ...

  • Answered by AI
  • Q17. Write a query to find name of authors who have written more than 10 books. Table - Bookauthhor Column - Book Column - Author
  • Ans. 

    Query to find authors who have written more than 10 books

    • Use the GROUP BY clause to group the records by author

    • Use the HAVING clause to filter the groups with a count greater than 10

    • Join the Bookauthor table with the Author table to get the author names

  • Answered by AI
  • Q18. Write a program to return the length of the longest word from a string whose length is even?
  • Ans. 

    This program returns the length of the longest word from a string whose length is even.

    • Split the string into an array of words using a space as the delimiter.

    • Iterate through the array and check if the length of each word is even.

    • Keep track of the length of the longest even word encountered.

    • Return the length of the longest even word.

  • Answered by AI
Round 3 - HR 

(3 Questions)

  • Q1. How much salary expectations?
  • Ans. 

    Answer the salary expectations question in an interview for a Java Developer position.

    • Research the average salary range for Java Developers in your location and level of experience.

    • Consider your qualifications, skills, and experience when determining your salary expectations.

    • Be realistic and flexible in your salary expectations, taking into account the company's budget and industry standards.

    • Provide a salary range rath...

  • Answered by AI
  • Q2. Do you have location constraints?
  • Ans. 

    No location constraints.

    • I am open to working in any location.

    • I am willing to relocate if required.

    • I do not have any personal or family commitments that tie me to a specific location.

  • Answered by AI
  • Q3. Why are you leaving this company?
  • Ans. 

    Seeking new challenges and growth opportunities.

    • Looking for a company that aligns better with my career goals.

    • Seeking a more collaborative and innovative work environment.

    • Desire to work on larger and more complex projects.

    • Want to expand my skill set and learn new technologies.

    • Seeking better work-life balance.

    • Company restructuring or downsizing.

    • Limited career advancement opportunities in current company.

  • Answered by AI

Interview Preparation Tips

Topics to prepare for Wissen Technology Java Developer interview:
  • DSA
  • Core Java
  • Java 8
  • Hashmap
  • Multithreading
  • OOPS
  • Synchronisation
  • Serialization
Interview preparation tips for other job seekers - Majorly questions are repetitive.
So focus on Core Java and Multi threading.
Java 8.

Practice easy and medium level questions from leetcode

Skills evaluated in this interview

Interview experience
4
Good
Difficulty level
Moderate
Process Duration
-
Result
-

I applied via Job Portal and was interviewed in Feb 2024. There was 1 interview round.

Round 1 - One-on-one 

(1 Question)

  • Q1. Given hackerank platform to test code
Interview experience
4
Good
Difficulty level
Moderate
Process Duration
Less than 2 weeks
Result
No response

I applied via Company Website and was interviewed in Jan 2024. There was 1 interview round.

Round 1 - Coding Test 

2 coding questions and 1 sql mcq

Interview Preparation Tips

Topics to prepare for Wissen Technology Java Developer interview:
  • Java
  • Core Java
  • Spring Boot
  • sql
Interview experience
3
Average
Difficulty level
Moderate
Process Duration
Less than 2 weeks
Result
Selected Selected

I applied via Referral and was interviewed before Feb 2023. There were 2 interview rounds.

Round 1 - Aptitude Test 

Couple of quants and technical mcqs and one coding question.

Round 2 - Technical 

(2 Questions)

  • Q1. Internal implementation of hashmap.
  • Ans. 

    HashMap is internally implemented using an array of linked lists.

    • HashMap uses an array to store key-value pairs

    • Each array index is called a bucket

    • Each bucket can store multiple key-value pairs using a linked list

    • Hashing is used to determine the index of the array for a given key

    • If multiple keys hash to the same index, they are stored in the same bucket

  • Answered by AI
  • Q2. What is immutable class how can we create it?
  • Ans. 

    An immutable class is a class whose objects cannot be modified after they are created.

    • To create an immutable class, make the class final so that it cannot be extended.

    • Make all the fields private and final, so they cannot be modified.

    • Do not provide any setter methods, only provide getter methods.

    • If the class contains mutable objects, make sure to return a copy of the object instead of the original.

    • Ensure that the class ...

  • Answered by AI

Interview Preparation Tips

Interview preparation tips for other job seekers - Good company to work, prepare core java nicely.

Skills evaluated in this interview

Wissen Technology Interview FAQs

How many rounds are there in Wissen Technology Java Developer interview?
Wissen Technology interview process usually has 2-3 rounds. The most common rounds in the Wissen Technology interview process are Technical, One-on-one Round and Coding Test.
How to prepare for Wissen Technology Java 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 Wissen Technology. The most common topics and skills that interviewers at Wissen Technology expect are Java, Multithreading, RDBMS, Algorithms and Data Structures.
What are the top questions asked in Wissen Technology Java Developer interview?

Some of the top questions asked at the Wissen Technology Java Developer interview -

  1. Parent class has run() and walk() . Parent run() - calls walk() Child Class ov...read more
  2. 2. What will happen if hashcode only returns a constant? How will it affect the...read more
  3. How to sort a list of students on the basis of their First na...read more
How long is the Wissen Technology Java Developer interview process?

The duration of Wissen Technology Java Developer interview process can vary, but typically it takes about less than 2 weeks to complete.

Tell us how to improve this page.

Wissen Technology Java Developer Interview Process

based on 21 interviews

2 Interview rounds

  • Coding Test Round
  • Technical Round
View more
Wissen Technology Java Developer Salary
based on 54 salaries
₹3 L/yr - ₹9 L/yr
24% less than the average Java Developer Salary in India
View more details

Wissen Technology Java Developer Reviews and Ratings

based on 2 reviews

4.4/5

Rating in categories

4.4

Skill development

3.7

Work-life balance

3.7

Salary

4.4

Job security

4.4

Company culture

3.7

Promotions

4.4

Work satisfaction

Explore 2 Reviews and Ratings
Java Developer

Bangalore / Bengaluru

7-10 Yrs

Not Disclosed

Java Developer

Mumbai

7-10 Yrs

Not Disclosed

Java Developer

Mumbai

7-10 Yrs

Not Disclosed

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