Introduction: Why You’re Still Failing Java Interviews
- What Interviews Actually Measure
- Where This Breaks: Real Market Example
- Why This Gets Harder in International Interviews
- What This Book Will Actually Do
- What This Book Does Not Cover
- How to Use This Book
- Final Point
- Next Step
Chapter 1: The Questions That Expose Weak Java Fundamentals
- What are the key OOPS Concepts?
- Differences Between Errors and Exceptions
- What are the differences between overriding and overloading?
- What is the benefit of Try-with-Resources in Java?
- Dynamic vs Static Polymorphism in Java
- Java 8 Interfaces
- Abstract Class VS Interface: Key Differences
- Difference between the final, finally and finalize keywords:
- == vs .equals() in Java
- Does Java pass Values by Reference or by value?
Chapter 2: Collections and Data Structures Under Pressure
- Data Structures: Sets vs. Lists
- When two objects are considered equal in a HashSet? Explain the equals() and hashCode() contract.
- How hashmap works internally?
- HashMap: hashCode() and equals() Contract
- How HashMap works in Java?
- When to Use ArrayList vs. LinkedList in Java?
Chapter 3: Advanced Java Concepts Interviewers Use to Filter Candidates
- Four Pillars of OOPs
- What Defines an an Immutable Class?
- What is a pure function?
- What are the main Concepts of a Stream in Java?
- What are annotations for metadata-driven development?
Chapter 4: Concurrency and Memory Questions That Separate Mid from Senior
- What is Garbage Collection?
- What is Deadlock and How to Prevent It?
- What are the Differences Between Stack vs Heap Memory?
- How to Prevent Deadlocks?
- Classic Deadlock Example
- What is ThreadLocal?
- What are the main concepts from the JVM Garbage Collection?
- Deadlock and Avoidance Strategies
- How does HashMap work internally and how does it handle collisions?
- Deadlock: Understanding and Prevention
Chapter 5: Architecture and Framework Questions That Reveal Your Level
- Design Patterns
- What is REST?
- What are the Difficulties in Developing a UI Framework?
- 10 Difficulties in Developing an API Framework
- HTTP Methods (GET, POST, PUT, PATCH, DELETE)
- POST vs PUT
- Explain Singleton and Builder
- How is Spring Boot Different from Spring?
- What is SOLID Principle in Software Development?
- What are the main reasons for using microservices?
Chapter 6: Testing and Code Quality: What Separates Mid-Level from Senior
- Different Types of Functional Tests
- What is the Difference Between Sanity and Regression Testing?
- What are the Components of Test plan and test strategy?
- What is BDD and What Are Its Advantages and Disadvantages?
- What is priority and severity in a bug report. Give an example for a bug which is high priority but not severe and vice versa?
- Testing techniques
- Types of performace testing
- Load Testing vs. Stress Testing
- How to check 3rd party libraries with random failure issue?
- How to Diagnose Random Failures?
- Diagnosing 3rd Party Library Random Failures
Chapter 7: Database Questions That Test Real-World Thinking
- What are the Differences Between INNER JOIN vs OUTER JOIN?
- What is Data Manipulation Language (DML)?
- Data Control Language (DCL)
- Transaction Control Language (TCL)
- How would you optimize a slow-performing SQL query? What steps would you take to diagnose and improve it?
- Describe the trade-offs between database normalization and denormalization. When would you choose one over the other?
- How do you handle database migration and schema evolution in production systems?
- Explain ACID properties and their importance in enterprise applications
Chapter 8: Methodology and Team Questions That Reveal How You Work
- How Big Should a Software Development Team Be?
- Disadvantages of Agile
- What is Agile and What Are Its Main Benefits?
- Compare and contrast Scrum and Kanban. When would you choose one over the other?
- How do you handle changing requirements in the middle of a sprint? What approaches have you used to minimize disruption?
- What metrics do you find most valuable for measuring team productivity in an agile environment? How do you prevent metric-driven dysfunctions?
- How do you approach technical debt? What strategies have you used to manage and reduce it?
- What’s your approach to code reviews? How do you ensure they’re both thorough and constructive?
Chapter 9: DevOps and Delivery: Are You Production-Ready?
- What is CI/CD and its advantages?
- What are the key components of a CI/CD pipeline?
- How do you implement blue-green deployments?
- What strategies would you use for database changes in a CI/CD pipeline?
- How would you handle secrets and sensitive configuration in a CI/CD pipeline?
- What strategies would you use for database changes in a CI/CD pipeline?
- How would you handle secrets and sensitive configuration in a CI/CD pipeline?
Next Steps: What Happens If You Don’t Fix This
- The Next Step
- If You’re Not Ready Yet
- Final Thought
