Custom ClassLoader Java Interview Question

Most developers prepare for Spring Boot interviews the wrong way. They focus on syntax… but ignore fundamentals. These 5 questions alone can decide your selection 👇 1. What is @SpringBootApplication? 2. Difference between @Component vs @Service vs @Repository? 3. What is Dependency Injection and why is it important? 4. What is Bean Scope in Spring? 5. How does Spring Boot auto-configuration actually work? If you can explain these clearly with examples, you’re already ahead of 70% candidates. Focus on concepts, not just code. Follow for more 🚀 #Java #SpringBoot #BackendDeveloper #Microservices #SoftwareEngineering

🚀 Spring Boot Interview Preparation (2+ Years Experience) Preparing for backend interviews? Here are some **must-know Spring Boot concepts** every developer should master 👇 🔹 **Core Concepts** 1. What is auto-configuration in Spring Boot? 2. How does Spring Boot reduce boilerplate configuration? 3. Role of `@SpringBootApplication`? 4. What are Spring Boot starters? 5. Explain Spring Boot lifecycle 🔹 **Dependency Injection & Beans** 6. Difference between `@Component`, `@Service`, `@Repository`, `@Controller` 7. Bean scopes in Spring 8. Constructor vs Field Injection 9. What is `@Qualifier`? 10. Circular dependencies in Spring 🔹 **REST API & Web Layer** 11. `@RestController` vs `@Controller` 12. Global exception handling 13. What is `@ControllerAdvice`? 14. Content negotiation 15. Validation using `@Valid` 🔹 **Spring Security** 16. How Spring Security works internally 17. Role of SecurityFilterChain 18. JWT authentication 19. Authentication vs Authorization 20. Securing REST APIs 🔹 **Spring Data JPA** 21. JpaRepository vs CrudRepository 22. Lazy vs Eager loading 23. N+1 problem 24. Custom queries in JPA 25. How `@Transactional` works #Java #SpringBoot #BackendDeveloper #InterviewPreparation #Developers #TechCareers

Cracking Spring Boot Interviews (3 Years Experience) I recently went through a curated list of top Spring Boot interview questions, and one thing became clear: Interviews are NOT about memorizing annotations They are about understanding why things work Here are some key insights every 3 YOE developer should know 👇 1. Auto-Configuration is the backbone Spring Boot automatically configures your app based on dependencies — reducing boilerplate and speeding up development. 2. @SpringBootApplication = Power Combo It combines configuration, component scanning, and auto-configuration in one annotation. 3. Stereotype annotations matter @Component → generic @Service → business logic @Repository → database layer (+ exception handling) 4. Async & Performance Using @Async enables parallel execution using separate threads — critical for scalable systems. 5. WebClient > RestTemplate (modern apps) Non-blocking calls = better performance in high-load systems. 6. Real-world problem solving Handling circular dependencies using @Lazy or setter injection shows deeper understanding. 7. Testing matters @DataJpaTest helps test only repository layer with in-memory DB. 8. Bean scopes define lifecycle Singleton, Prototype, Request, Session — each impacts performance & behavior. My Takeaway: If you want to crack interviews at this level, focus on: ✔ Internal working ✔ Real-world use cases ✔ Trade-offs (blocking vs non-blocking, sync vs async) Not just definitions. Next Step: I’m starting a System Design + Spring Boot series where I’ll connect these concepts with real-world architectures. Follow along if you're preparing for backend roles #SpringBoot #Java #BackendDevelopment #SystemDesign #InterviewPreparation #SoftwareEngineering

You don’t get rejected in senior interviews because you don’t know Java. You get rejected because: 👉 You jump to answers without diagnosing the problem. I compiled real production-style questions asked in interviews, including: - JVM issues - Retry storms - ThreadLocal bugs - Spring failures This carousel is Part III of the series. Full deep-dive articles: - Part I: [https://lnkd.in/gV37rZr9] - Part II: [https://lnkd.in/gMp59AQV] - Part IIIA: [https://lnkd.in/graSMnv5] Curious — what’s the toughest production issue you’ve debugged

I am looking for work. And before I started to look for work again I thought it was a good idea to set up a repository to showcase how I view problems from a long term perspective instead of a 1 or 2 day coding task. https://lnkd.in/g_tVY67D is a monorepo that simulates a youtube like company.  It captured metrics for “videos" played, who watched them, and allowed users to comment on the “videos”. In this example the media in question will just be represented by a looping gif.   It does this using mysql, postgres, redis, and kafka for data storage and messaging, along with about 8 custom applications, java for backend and typescript for front end.  All applications can be built using one gradle command (./gradlew build), and the entire stack can run by just running `run_locally.sh` if you are on a mac.  I have a run_locally.bat for windows, but I haven’t tested it out and am assuming it won’t work. The entire stack can be run on a mac with 16gb of ram. The entire stack demonstrates how using a monorepo approach you can use naming conventions, gradle plugins, and submodules to quickly introduce new executable, minimize context windows, refactor consistently and quickly create integration tests that focus on testing business concerns. For example * Plugins For Build Conventions * Using plugins to automatically generate open api documentation and setup base spring boot dependencies The convention https://lnkd.in/g_nv8S6E How it’s used https://lnkd.in/gqt8hRm8 This allows build scripts to focus on what is unique for the application instead of boiler plate * Integration Tests As It’s Own Submodule * Instead of creating an integrationTest task, it is its own distinct module.  This means you can bring in multiple microservices and test them in a single test. For example the following test https://lnkd.in/gxV6gwhi Tests that for a unique user, and piece of media, that when a user plays and stops viewing that piece of media the metrics are captured.  This tests that information went through the whole stack, (mysql, kafka, postgres and most of the microservices). These techniques, among others, are what I hope to bring to the table at your company to reduce the size of context windows for your ai agents, increase readability, simplify testing, simplify deployments, centralize documentation, and reduce the amount of time spent talking about the tech stack instead of improving your product.

🚀 Most Asked Linked List Interview Questions (Java / DSA) If you’re preparing for FAANG or product-based companies, Linked Lists are a must-know topic. Here are the most frequently asked interview questions you should practice: 🔹 Reverse a Linked List (iterative + recursive) 🔹 Detect a cycle in a linked list (Floyd’s Cycle Detection) 🔹 Find the middle of a linked list 🔹 Merge two sorted linked lists 🔹 Remove Nth node from end of list 🔹 Check if a linked list is a palindrome 🔹 Find intersection point of two linked lists 🔹 Detect and remove loop in a linked list 🔹 Flatten a multilevel linked list 🔹 Add two numbers represented by linked lists 💡 Why Linked Lists matter: They test your understanding of pointers, memory management, and problem-solving under constraints. 📌 Tip: Don’t just memorize solutions—understand pointer manipulation deeply. What’s your favorite linked list problem to solve?

🚀 I was asked this in a Java interview… and many people fail here 👉 What is the difference between @Component, @Service, and @Repository? Here’s the simplest explanation 👇 💡 All three are Spring stereotypes They tell Spring to create beans automatically. 🔁 Difference: 👉 @Component → Generic (any class) 👉 @Service → Business logic layer 👉 @Repository → Database layer (handles exceptions) 🔥 Why this matters: Interviewers check if you understand design, not just annotations. --- If you're preparing for Java interviews, don’t skip this. Follow for real backend interview prep 🚀

I realized something during backend interview prep… 👉 Knowing concepts is NOT enough. You must know: What happens in production How systems fail How to design scalable architecture That’s what interviewers actually test. So I created a PDF focused on: ✔ Real scenarios ✔ System design ✔ Spring Boot internals ✔ Backend architecture 👉 Link: https://lnkd.in/gbF6u9ni 🎁 Use JAVA25 to get 15% OFF. Think like an engineer. Not a student. #BackendEngineering #JavaDeveloper

𝟰𝟬 𝗦𝗽𝗿𝗶𝗻𝗴 𝗕𝗼𝗼𝘁 𝗔𝗻𝗻𝗼𝘁𝗮𝘁𝗶𝗼𝗻𝘀. 𝗢𝗻𝗲 𝗰𝗮𝗿𝗼𝘂𝘀𝗲𝗹 🎉 Most devs 𝗺𝗲𝗺𝗼𝗿𝗶𝘇𝗲 annotations. Top devs know 𝗪𝗛𝗬 they exist. I built this carousel so you never blank out in an interview again. 𝟰𝟬 𝗮𝗻𝗻𝗼𝘁𝗮𝘁𝗶𝗼𝗻𝘀 — each explained in 𝗽𝗹𝗮𝗶𝗻 𝗘𝗻𝗴𝗹𝗶𝘀𝗵: • 𝗕𝗲𝗮𝗻 𝗪𝗶𝗿𝗶𝗻𝗴 (@Autowired, @Qualifier, @Lazy...) • 𝗦𝘁𝗲𝗿𝗲𝗼𝘁𝘆𝗽𝗲𝘀 (@Service, @Repository, @Component...) • 𝗪𝗲𝗯 & 𝗥𝗘𝗦𝗧 (@GetMapping, @RestController...) • 𝗖𝗼𝗻𝗳𝗶𝗴, 𝗔𝘀𝘆𝗻𝗰, 𝗖𝗮𝗰𝗵𝗶𝗻𝗴, 𝗝𝗦𝗢𝗡 & more 𝗦𝘄𝗶𝗽𝗲 → 𝗦𝗮𝘃𝗲 → 𝗦𝗵𝗮𝗿𝗲 with someone preparing for interviews. 💬 Which annotation confuses you the most? Drop it below 👇 #SpringBoot #Java #BackendDevelopment #InterviewPrep #JavaDeveloper #PakistaniDevelopers

Engineering With Java newsletter now covers 58 real world use case based interview questions 🥳 If you like to practice these questions , checkout : https://lnkd.in/gW5kQ6Xf #java #spring #springboot #interview