explain hashing technique used by Java, explain hashmap, explain log(n) time complexity, explain sorting algorithm used by Arrays.sort().

First Round (Technical Interview): Project-related: -Are the classes in my project immutable? -Difference between PUT and POST API calls. -What happens if a POST API is called repeatedly? Java Coding & Concepts: -Declaring an array of Employee objects (name, salary, age). -Retrieve employees with a salary > 50K and age < 25 using a for-loop and Lambda expression. -Functional interfaces. -LinkedHashSet – Implementation and adding elements. -Difference between checked and unchecked exceptions. -Difference between String and StringBuilder. -Thread safety and the role of the synchronized keyword. -Merging two unsorted arrays into a sorted array. -Reverse a sorted array without using built-in functions. -Difference between Inheritance and Composition. -Spring Annotations – Difference between @Bean and @Component. Problem-Solving & Behavioral Questions: -Approach to solving a problem with limited resources. -A logic puzzle: Identifying the correct switch for three bulbs in another room with minimal trips. Second Round (Technical + HR Interview): NoSQL & Cassandra: -Basics of NoSQL databases. -Primary key attributes in Cassandra. -Identifying the node containing specific data when it is multiplied. -Replication at the keyspace level in Cassandra. Spring & Java: -Dependency Injection. -Features of Java 8 and Java 17. -Stereotypical annotations in Spring. -Beans and interaction with databases in Spring applications. Coding Questions: -Sorting an array of squared elements (including negative numbers). Git: -How to resolve merge conflicts. Personal Project Discussion: -Challenges faced and how they were overcome. -Features used in the project. HR Questions: -Problems faced (technical or personal) and how I handled them. -What I have been doing since graduation. -How I managed my time during the gap period.

Basic Java OOPS core questions