Sandesh. Gundoji

@SumitM_X @SumitM_X Hi sumit, I have registered for above session. But i did not receive any confirmation details.

AI for Java developers 6 PM IST Sunday 8th March Link to register : topmate.io/interviewswith…

Why does “works on my machine” happen? Because .m2 cache hides dependency conflicts that CI reveals.

Production issue story 👇 Wrong dependency version pulled via transitive dependency. App compiled. Runtime crashed. Solution? mvn dependency:tree

Q: What are transitive dependencies? A: If A depends on B, and B depends on C, Maven automatically brings C into A. Dependency graph resolution is automatic.

Q: What happens internally when you run mvn install? A: 1.Executes lifecycle up to install 2.Compiles code 3.Runs tests 4.Packages artifact 5.Stores artifact in local repo It’s a phase chain execution.

Q: Why do we use mvn clean? A: It deletes the target/ directory. Prevents stale .class files from affecting the new build. Clean ensures deterministic builds.

Q: What happens internally when you run mvn install? A: 1.Executes lifecycle up to install 2.Compiles code 3.Runs tests 4.Packages artifact 5.Stores artifact in local repo It’s a phase chain execution.

Q: What is Super POM? A: Maven has a hidden default POM called Super POM. Your project POM inherits from it. That’s where default plugins & repos come from. #JavaInterview #Maven #BuildTools

Q: Difference between mvn clean install and mvn clean package? A: package → builds JAR/WAR install → builds + copies artifact to local .m2 repo Install is for reuse by other local projects. #JavaInterview #Maven #BuildTools

Interview trap 🚨 “Difference between mvn clean install and mvn clean package?” If you say “both create jar” follow-up coming 😬 #JavaInterview #Maven #BuildTools

If you can’t explain Maven lifecycle phases in order, you’re not ready for backend interviews. validate → compile → test → package → verify → install → deploy #JavaInterview #JavaDeveloper #DevTwitter

Spring scopes aren’t hardcoded. You can define Custom Scopes. Custom scope = Custom lifecycle + Custom storage + Custom cleanup Spring gives you the hooks. You define the rules.

Spring also supports WebSocket scope 👀 Yes, it exists, most people never mention it. WebSocket scope = one bean per WebSocket session Perfect for: ✔ Live updates ✔ Chat apps ✔ Streaming data

Application scope ≠ Singleton. Singleton → per ApplicationContext Application → per ServletContext Use Application scope when: ✔ Data shared across all users ✔ App-wide caches ✔ Read-heavy, rarely-changing data

Session scope = one bean per HTTP session Backed by the servlet container. If you use Session scope in microservices, ask yourself: “Do I really need server-side state?” 🤔 Spring resolves scope before bean creation using metadata in BeanDefinition. Scope is a container task.

Request scope = one bean per HTTP request Stored internally using RequestAttributes. Web-only. Context matters. Request scope = one bean per HTTP request Stored internally using RequestAttributes. Web-only. Context matters.

Prototype scope means: Spring creates the object… and then says “Good luck 🤝” No lifecycle management after creation. Use Prototype when: ✔ Stateful ✔ Short-lived ✔ Not thread-safe And never inject it directly into Singleton without a proxy.

Default Spring scope = Singleton One bean per ApplicationContext, not per JVM. Use Singleton when: ✔ Stateless ✔ Thread-safe ✔ Shared across requests 90% of Spring beans should be Singleton.

Spring doesn’t eagerly create everything. It eagerly creates BeanDefinitions.

Spring resolves conflicts at BeanDefinition level, not object level. @Primary, @Qualifier? Metadata decisions. Why does @Conditional work? Because Spring decides whether to register a BeanDefinition at all. No definition → no bean.