You already know interfaces in Java. A Functional Interface is simply an interface with exactly one abstract method — nothing more. This constraint is intentional and it allows Java to represent behavior as a value. Runnable is a classic example. It defines a single contract: void run(); Because there is only one abstract method, the compiler can infer intent and accept a lambda as its implementation. Runnable task = () -> {   System.out.println("Executing task for Anwer Sayeed"); }; The lambda doesn’t replace Runnable. It implements its contract, concisely. This design choice is what enabled Java’s functional style without breaking its object-oriented foundations. #Java #FunctionalInterface #Runnable #LambdaExpressions #JavaDeveloper #CleanCode #Multithreading

Abstract Class vs Interface in Java – Quick Tip Abstract Class: Can have methods with or without code. Supports shared behavior. A class can extend only one. Interface: Usually methods without code. Defines a contract. A class can implement multiple. Remember: Abstract → “is-a” Interface → “can-do” Mastering this helps you write clean, reusable, and maintainable code! 💻 #Java #OOP #SOLID #BackendDevelopment #ProgrammingTips

🔥 DAY 17 – Cleaner Java with Streams Java Streams make collection handling elegant. Example: List<String> names = users.stream() .map(User::getName) .collect(Collectors.toList()); Why use Streams? ✔ Less boilerplate ✔ Functional style ✔ Cleaner logic But don’t overuse it for complex logic. Readable > Fancy. #Java #CleanCode

🤔 Do We Really Need So Many Frameworks in Java? Sometimes I wonder… Are we solving problems, or just adding more layers? A simple feature today often looks like: ➡️ Spring Boot ➡️ Multiple dependencies ➡️ Config files ➡️ Annotations everywhere Don’t get me wrong — frameworks are powerful. They save time and standardize development. But I’ve also seen this 👇 ❌ Over-engineered solutions for simple problems ❌ Developers struggling to debug because “framework magic” hides everything ❌ Less focus on core Java fundamentals 👉 My takeaway: Frameworks should support your understanding, not replace it. Because at the end of the day: If you don’t understand what’s happening underneath… You’re just assembling pieces, not building systems. 💬 What’s your take — do frameworks simplify development or make it unnecessarily complex? #Java #SoftwareEngineering #SpringBoot #CleanCode #JavaDeveloper #TechDebate #BuildInPublic

Your Java code might be slow before it even runs. ☕ Most beginners ignore object creation cost. They create new objects inside loops. Thousands of objects appear in seconds. Garbage collector now has extra work. Small inefficiency becomes large latency. Rule: reuse objects when possible in hot paths. Takeaway: memory churn quietly slows backend systems. 🧠 Where did you accidentally create objects in a loop? #CoreJava #JavaPerformance #BackendDevelopment

Excellent article by Jonas Norlinder with a deep dive on the existing garbage collectors, and insight on improvements coming in Java 26. https://lnkd.in/dpyr82Jy #Java #Spring #SpringBoot #Kotlin #GarbageCollector

Missed posting yesterday. Used the time to revise Java fundamentals. Revision in Java isn’t about rereading syntax. It’s about rediscovering why things work the way they do. Yesterday’s revision focused on: • How memory is managed inside the JVM • Why equals() matters beyond comparisons • How exceptions propagate through method calls • The real difference between == and .equals() These topics feel small — until they cause real bugs. Frameworks change. APIs evolve. But Java fundamentals stay relevant. Revising basics is not going backward. It’s upgrading how you think. Back today. Building on stronger foundations. #Java #CoreJava #JVM #BackendDevelopment #SoftwareEngineering #LearningInPublic #BuildInPublic

📌 Part 2: Processes vs Threads (And Why Java Developers Must Understand This) This is where backend engineers often get confused. 🔹 What is a Process? A Process = Independent program in execution. It has: Own memory space Own heap Own stack Own resources Example: If you run: Chrome IntelliJ MySQL Each is a separate process. In Java: When you start JVM → OS creates a process. 🔹 What is a Thread? Thread = Lightweight unit of execution inside a process. Threads share memory Threads share heap But each has its own stack In Java: Thread t = new Thread(); You are asking OS (through JVM) to create a native thread. 🔥 Why This Matters in Backend Development? Spring Boot app: One process (JVM) Multiple threads (request handling) Tomcat: Uses thread pool Each HTTP request → handled by one thread So when you configure: server.tomcat.threads.max=200 You are indirectly controlling OS-level threads. ⚠️ Context Switching When CPU switches from: Thread A → Thread B OS: Saves registers Saves program counter Loads new context This costs time. Too many threads → Too much context switching → Performance drop. This is why: ExecutorService Thread pools Virtual threads (Project Loom) exist. #Java #JVM #JavaDeveloper #BackendDevelopment #SpringBoot #Concurrency #Multithreading #PerformanceEngineering #MemoryManagement #Threading