4-6 years Experience Interview Questions

Questions:

1. 1.1. What is the difference between HashMap and ConcurrentHashMap? 2. Can you explain how HashMap works internally in Java? 3. What is the difference between Comparable and Comparator interfaces? 4. What is the Java 8 Stream API? Can you give a real-time example of how it is used? 5. What is the difference between Checked Exceptions and Unchecked Exceptions? 6. What is the difference between Method Overloading and Method Overriding? 7. Can you explain the lifecycle of a thread in Java multithreading? 8. What is ExecutorService and why is it used? 9. What is a Deadlock in Java, and how can it be prevented? 10. What is the difference between final, finally, and finalize?

Questions:

1. 1.Explain the difference between HashMap and ConcurrentHashMap. When would you use each? How do you handle transactions in Spring Boot? Explain the @Transactional annotation. Design a REST API for an e-commerce cart system. Include endpoints and explain authentication. What is the difference between fail-fast and fail-safe iterators in Java Collections? Write a SQL query to find the second highest salary from an Employee table. Explain microservices architecture and how you would handle inter-service communication. How do you implement exception handling in Spring Boot? Give examples of custom exceptions. Describe a situation where you optimized database queries. What approach did you take? What are the SOLID principles? Explain with real-world examples. How would you implement authentication and authorization in a Spring Boot application?

Questions:

1. 1.How do you identify unnecessary re-renders? When should you use code splitting? How does lazy loading work in React? What are the trade-offs of memoization? How does React handle large lists efficiently? Difference between virtualization and pagination

Questions:

1. 1.What are the important features of Java 17? What is JWT? How does JWT work in a real-time application? How is authentication handled in microservices? What is microservices architecture? How do microservices communicate with each other? How does Kafka integrate with a Spring Boot application? Difference between synchronous and asynchronous communication How do you handle data consistency across microservices? What happens if one service goes down? What are the advantages and disadvantages of stored procedures? What are Azure Functions? Why do we use serverless architecture? Write a program to print non-repeated characters in a string Why do we use stored procedures? How do you handle failures in Kafka-based systems?

Questions:

1. 1.1)Explain the 3 array methods of JS 2)Write JS code to find the first non occured letter in a string 3)Write Playwright code to handle multiple windows and perform actions on new page 4)Explain the steps to open allure reports 5)Explain api authentication methods 6) Difference between put and patch 7)Explain filter,reduce,map methods 8)Explain git process- push pull steps of merging and cloning 9)Explain debug process in playwright 10) Explain different types of locators