ISS STOXX | Mumbai | Experienced Software Engineer | Rejected
Summary
I was rejected for the Experienced Software Engineer role at ISS STOXX in Mumbai after multiple rounds, including extensive Java trivia and one Data Structures & Algorithms problem.
Full Experience
This is third company which I have got rejection from.
Round 0: Screening round with HR
Role expectations, salary expectations and number of interview rounds to be conducted
Round 1: Online tech interview
This was more of a trivia round, below are the questions asked
- Current org work related discussion
- What is String pool
- Implement Singleton pattern
- Which Java version are you familiar with, what new features were added in Java17, when would you use sealed classes
- What is try-with-resource in Java
- using Java8 Feature return one hash-map with key as Word and value as Frequency of that word.
List<String> list = Arrays.asList("apple", "banana", "apple", "orange", "banana", "apple");
Answer:
Map<String, Integer> frequencyMap =
list.stream()
.collect(Collectors.toMap(
word -> word,
word -> 1,
Integer::sum
));
Round 2: Onsite tech interview
This was Java Trivia + DSA round and was supposed to be the last tech round.
- What happens in String pool, why are Java Strings immutable
- What happens to a class which is declared as final
- Can we initialise a variable declared as final in constructor
- Difference between abstract classes and interfaces
- Using java streams feature, convert an array containing duplicate elements to array containing unique elements
- What datastructure is used inside of HashMap?
- What is ConcurrentHashMap?
- Explain significance of equals() and hash() methods wrt Hashing.
- What would happen in case of collisions?
- Which design patterns have you implemeted at your workplace
- Merge Overlapping intervals problem
SPECIAL NOTE: The job description had mentioned Spring Boot and React in tech stack, but no questions were asked from these parts even though job title was Software Engineer and not Java Developer
Interview Questions (15)
Explain String Pool in Java
Explain what the String pool is in Java.
Implement Singleton Pattern
Implement the Singleton design pattern.
Java 17 Features and Sealed Classes
Discuss familiarity with Java versions, new features added in Java 17, and when one would use sealed classes.
Explain try-with-resource in Java
Explain what the try-with-resource statement is in Java.
Word Frequency using Java 8 Streams
Using Java 8 Streams, return a HashMap with words as keys and their frequencies as values from a given list of strings. Example: List<String> list = Arrays.asList("apple", "banana", "apple", "orange", "banana", "apple");
String Pool and Immutability in Java
Explain what happens in the String pool and why Java Strings are immutable.
Behavior of a final class in Java
Explain the implications of declaring a class as final in Java.
Initializing final variable in constructor
Can a variable declared as final be initialized within a constructor in Java?
Abstract Classes vs. Interfaces in Java
Explain the differences between abstract classes and interfaces in Java.
Remove Duplicates using Java Streams
Using Java Streams, convert an array containing duplicate elements to an array containing only unique elements.
Internal Data Structure of HashMap
What data structure is used internally in a Java HashMap?
Explain ConcurrentHashMap
Explain what ConcurrentHashMap is in Java.
Significance of equals() and hashCode() for Hashing
Explain the significance of the equals() and hashCode() methods with respect to hashing in Java.
Handling Collisions in Hashing
What would happen in case of collisions when using hash-based data structures?
Merge Overlapping Intervals
Solve the Merge Overlapping Intervals problem.