Intellicheck Java Developer Interview: Rounds, Questions and Preparation

What the job involves

As a Java Developer at an Indian IT services or fast-growing product company like Intellicheck, you will build and maintain server-side applications using Java, Spring Boot, and databases. Day to day work includes writing REST APIs, fixing bugs, participating in code reviews, and collaborating with testers and senior developers to deliver client projects on time.

Role and Technical Knowledge

1. 1

   Explain the difference between ArrayList and LinkedList in Java. When would you use each?

   Mention ArrayList uses a dynamic array for fast random access, while LinkedList uses nodes for fast insertions and deletions. Give a real example like using ArrayList for storing API response lists.

2. 2

   What is the difference between an abstract class and an interface in Java 8 and above?

   Cover that interfaces can have default and static methods since Java 8, while abstract classes can have constructors and state. Explain when to choose one over the other.

3. 3

   How does Spring Boot simplify building a REST API compared to plain Spring?

   Mention auto-configuration, embedded servers like Tomcat, and starter dependencies. Give an example of a simple @RestController with @GetMapping.

4. 4

   Write a SQL query to find the second highest salary from an Employee table.

   Use a subquery with MAX or LIMIT with OFFSET. Explain the logic clearly and mention handling duplicate salaries.

Practical Scenarios

1. 5

   You are asked to fix a bug where a REST API returns 500 error only for some users. How do you debug it?

   Talk about checking server logs, reproducing the issue with the same input, and using breakpoints or logging. Mention checking null values and database constraints.

2. 6

   Your senior asks you to add a new field to an existing API response without breaking old clients. What do you do?

   Explain adding the field as optional and keeping backward compatibility. Mention versioning the API if needed and updating documentation.

3. 7

   You need to connect a Java application to a MySQL database. What steps and libraries would you use?

   Mention JDBC driver, connection URL, username and password, and using Spring Data JPA or JdbcTemplate. Talk about connection pooling with HikariCP.

4. 8

   How would you write a unit test for a method that calculates employee bonus based on salary and years of service?

   Use JUnit and assert expected values for different inputs. Mention edge cases like zero years or negative salary and using Mockito if dependencies exist.

Behavioural and Situational

1. 9

   Tell me about a time you worked in a team on a college project and faced a conflict. How did you handle it?

   Use the STAR method. Focus on listening, finding a middle ground, and keeping the project on track. Avoid blaming teammates.

2. 10

   You are assigned a task with a technology you have never used before. How do you approach it?

   Show willingness to learn by reading official documentation, watching tutorials, and asking seniors for guidance. Mention breaking the task into smaller parts.

3. 11

   Describe a situation where you missed a deadline. What did you learn?

   Be honest about the reason, show you communicated early, and explain the concrete step you took to avoid repeating it, like better time estimation.

4. 12

   Why do you want to work as a Java Developer in an IT services company rather than a product company?

   Highlight exposure to multiple clients, structured training, and learning opportunities. Connect it to your interest in solving diverse business problems.

HR and Company Fit

1. 13

   Are you willing to relocate to any city in India or work in shifts based on client requirements?

   Answer clearly and positively if you are flexible. If not, explain your constraints honestly but show willingness to adjust for short periods.

2. 14

   What do you know about our company and why do you want to join us?

   Research the company's services, recent projects, and values. Mention specific things like their training program or client base, not just generic praise.

3. 15

   Where do you see yourself in three years as a Java Developer?

   Show growth from junior developer to handling modules independently or mentoring freshers. Mention learning advanced frameworks and contributing to design.

4. 16

   Do you have any questions for us?

   Ask about the training period, project allocation process, or technologies used. Avoid asking only about salary or leave policy in the first round.