Guardian

Role: Java Developer

College: Not Specified

Interview Date: November 2021 (Based on video upload/discussion date)

Interview Type: Not Specified (Likely Full-Time, Off-Campus)

Result: Selected (Implied by video title)

Difficulty: Not Specified

Rounds: Multiple technical rounds (implied by detailed Q&A)

Topics Asked: Java (Core Java, OOPs, Multithreading, String handling, Collections), Spring Boot, Microservices, REST APIs, SQL, Docker, Kubernetes, Kafka, JUnit, Mockito, Git, Jenkins, Jira, Grafana, Agile Methodology

Experience:

A Java Developer with 5.9 years of experience discussed their interview experience for a Java Developer role at Guardian Life. The discussion covered a wide range of technical topics.

• **Java Concepts:** Questions included "Is HashMap synchronized or not?" (Answer: No, use Collections.synchronizedMap or ConcurrentHashMap), "Explain types of access modifiers" (Public, Private, Default, Protected, with detailed explanations for Private and Protected), "Is String mutable or immutable?" (Answer: Immutable, with explanation on how values are "changed").
• **Coding Example:** The candidate was asked to write a short coding example for inheritance.
• **Multithreading:** Discussion on how to ensure thread execution order using `join()` method (e.g., T1.join(), T2.join() for T2 to run after T1).
• **Database/SQL:** Questions included finding the second highest salary of an employee using an SQL query, and explaining different types of joins (Inner, Outer, Left, Right, Self Join). The difference between Primary Key (cannot have null) and Unique Key (can have one null) was also discussed.
• **Frameworks & Tools:** The candidate mentioned experience with Java 8, Spring Boot, Microservices, Docker, Kubernetes, Kafka for inter-service communication, REST, JUnit, Mockito for unit testing, Git, Jenkins, Jira for code maintenance, and Grafana for logging and monitoring. They also worked in an Agile methodology.

The interviewer reconfirmed the candidate's experience and then proceeded with detailed technical questions. This indicates a thorough technical evaluation focusing on core Java, related frameworks, and database knowledge.