Java Developer Interview Questions (Beginner to Advanced + Video Screening)

Introduction

Hiring the right Java Developer requires assessing technical knowledge, practical experience, and problem-solving ability. Effective screening helps hiring managers and recruiters identify candidates who can deliver reliable, maintainable Java applications.

This guide presents role-specific Java Developer interview questions across basic, intermediate, and advanced levels, and includes pre-screening one-way video interview questions ideal for structured candidate evaluation.

Java Developer Interview Questions

Basic Java Developer Interview Questions

• Explain the difference between JDK, JRE, and JVM.
• What are the main principles of object-oriented programming and how does Java implement them?
• Describe the difference between an interface and an abstract class in Java.
• How does the Java memory model organize heap and stack memory for an application?
• What is the purpose of the equals() and hashCode() methods, and why must they be consistent?
• Explain checked vs unchecked exceptions and when to use each type.
• How do generics improve type safety in Java? Provide a simple example.
• What are the common collection interfaces in Java and when would you use ArrayList vs LinkedList?

Intermediate Java Developer Interview Questions

• Describe how you would build a RESTful API in Spring Boot and list key annotations you would use.
• How would you identify and fix a memory leak in a Java application running in production?
• Explain how to use Java Streams to process a list of objects and give an example of filtering and mapping.
• Describe the pros and cons of using synchronized blocks vs java.util.concurrent locks.
• How do you implement pagination and sorting in a data access layer using JPA or JDBC?
• Walk through how you would design a retry mechanism for transient failures in external service calls.
• Explain how to manage transactions in Spring and when to use propagation settings like REQUIRES_NEW.
• How would you secure a Java web application — list authentication and authorization strategies you would apply.
• Describe a scenario where you optimized SQL queries called from Java and what changes you made.
• How do you perform asynchronous processing in Java and when would you choose CompletableFuture over ExecutorService?

Advanced Java Developer Interview Questions

• Explain the differences between JVM garbage collectors (G1, CMS, ZGC) and how to choose one for a high-throughput service.
• How would you design a high-availability, low-latency Java microservice to handle millions of requests per day?
• Describe strategies for JVM tuning in production for CPU, memory footprint, and pause time reduction.
• How do you approach diagnosing and resolving thread contention and deadlocks in a multi-threaded Java application?
• Explain how to implement back-pressure and rate-limiting for a Java-based streaming pipeline.
• Discuss techniques to optimize startup time and reduce memory consumption for Java containerised applications.
• How would you design distributed tracing and logging for a Java microservices architecture to aid debugging and SLA monitoring?
• Describe a migration strategy from a monolith to microservices for an existing Java application while minimizing risk.
• Explain how to use profiling tools (e.g., Flight Recorder, YourKit) to locate performance hotspots and what metrics you would inspect.
• How do you lead technical decisions and code quality improvements in a Java engineering team, including reviews and standards?

Pre-Screening Video Interview Questions for Java Developer

These concise one-way video interview questions are ideal for ScreeningHive and help capture candidates' communication, motivation, and experience before on-site interviews.

Use these prompts to standardise evaluation and reduce time-to-hire while ensuring consistent candidate responses.

1. Briefly introduce yourself and describe your most recent Java project, including your key responsibilities.

   Evaluates: communication, relevant experience, role fit.

2. Explain a significant technical challenge you solved in Java and the approach you took to resolve it.

   Evaluates: problem-solving, technical depth, ownership.

3. Describe your experience with Spring Boot and how you structure a typical service module.

   Evaluates: framework knowledge, design approach, coding practices.

4. How do you ensure code quality and maintainability in your team? Give examples of tools or processes you use.

   Evaluates: collaboration, quality processes, leadership.

5. What motivates you to work in Java development, and what are your learning goals for the next year?

   Evaluates: motivation, career goals, cultural fit.

Conclusion

These Java Developer interview questions enable hiring teams to assess candidates across conceptual knowledge, practical skills, and advanced architecture and leadership capabilities. Candidates can prepare targeted responses that demonstrate technical competence and problem-solving ability.

ScreeningHive accelerates hiring with faster screening, standardised evaluation, and efficient one-way video interviews that capture consistent candidate responses. Start using ScreeningHive to streamline your Java Developer hiring process and improve shortlist quality - sign up to begin standardised, scalable screening.