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Showing posts with the label Java Interview Preparation

Kubernetes & Amazon EKS Explained: A Beginner's Guide

Backend Deep-Dive · Beginner Friendly ~16 min read · Updated for 2026 · No prior experience required If the words Kubernetes and EKS have always felt like a wall of jargon, this is the guide that finally makes them click. We start from absolute zero — what a container even is — and build up, one idea at a time, until you can follow a single user request all the way through a real Amazon EKS cluster and back. Plain English, simple analogies, and a clear mental model instead of a pile of commands. Prefer to read? Everything in the video is written out below. Skim the table of contents and jump to whatever you need. TL;DR — the whole idea in six lines Containers pack your app and its environment together so it runs the same everywhere. Kubernetes is a manager that runs, heals, scales, and connects hundreds of containers for you. Every cluster has a Control Plane (the brain) and Worke...

ArrayList vs LinkedList in Java (Complete Guide for Interviews & Backend)

Most developers think they understand ArrayList and LinkedList … until an interviewer asks: “When would you use one over the other?” If you can’t confidently answer that — this guide will fix it. Watch Full Video Explanation What is a List in Java? A List is an ordered collection that: Maintains insertion order Allows duplicate elements Supports index-based access List<Integer> list = new ArrayList<>(); ArrayList Deep Dive 1. Internal Working ArrayList is backed by a dynamic array . 2. Contiguous Memory [10] [20] [30] [40] 👉 Enables fast access → O(1) 3. Size vs Capacity Size = 3 Capacity = 5 [10] [20] [30] [_] [_] 4. Resizing Mechanism New array created Capacity increases (~1.5x) Elements copied 👉 Resizing cost = O(n) 5. Performance Operation Time Complexity Access O(1) Insert (end) O(1) amortized Insert (middle) O(n) Delete O(n) ⚠️ Limitation Before: [10, 20, 30...

Java Exception Handling Best Practices (10 Rules Every Developer Must Know)

Exception handling is one of the most important concepts in Java programming. Whether you are a beginner learning Java or an experienced developer building real-world applications, understanding Java exception handling best practices is essential. Poor exception handling can cause several problems in applications such as: Hidden bugs that are difficult to detect Messy and confusing logs Difficult debugging during production issues Poor application design In this guide, you will learn: What exceptions are in Java The difference between checked and unchecked exceptions Important Java exception handling features 10 best practices used in real-world Java applications This guide is beginner-friendly and also useful for developers preparing for Java developer interviews . Watch the Video Explanation Watch the full video explanation below: Why Exception Handling Matters In Java, exceptions are how the system communicates failures or unexpect...

Java Collections Deep Dive

Introduction In real Java applications, we rarely work with just one value. Most of the time, we deal with: A list of users A set of permissions A map of IDs and objects A queue of tasks Handling such data using normal variables is not possible. This is where  Java Collections  come into the picture. Java Collections are ready-made data structures provided by Java to store, manage, and process multiple objects easily and efficiently. Understanding Java Collections is extremely important for: Backend development Real-world applications Java interviews Before starting interview preparation, it’s important to follow a structured  Java backend developer roadmap  so you don’t miss core fundamentals. Java Backend Developer Roadmap 2026 Why Java Collections Are Needed Before Java Collections, developers used  arrays . Arrays have multiple problems: Fixed size (cannot grow or shrink) No built-in methods for sorting or searching Difficult to manage large and dynamic data...