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LLD Masterclass: Designing a Split-Expense App (Splitwise)

1. Requirements (The Scope) A group expense sharing platform like Splitwise processes multi-user financial transactions. To model this systematically, we define the requirements under strict functional and engineering he…

May 22, 202610 min readAdvancedDeep Dive

#java#system-design#oop

HLD & LLD Mastery Course

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LLD Masterclass: Designing a Ride-Sharing Engine (Uber)

1. Requirements (The Scope) To design a production-grade ride-sharing engine like Uber or Lyft, we must translate ambiguous business processes into a precise technical design. In an advanced Low-Level Design (LLD) interv…

May 22, 202610 min read

Deep DiveHLD & LLD Mastery Course

#java#system-design#oop

JavaBeginner

Java is Strictly Pass-by-Value

1. The Core Concept Mental Model > Applying Staff-level engineering principles to build robust, production-grade software. One of the most misunderstood concepts in Java is how arguments are passed to methods. Let's clea…

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LLD Masterclass: Designing a Split-Expense App (Splitwise)

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LLD Masterclass: Designing a Ride-Sharing Engine (Uber)

Java is Strictly Pass-by-Value

Advanced Exception Handling

Generics and Type Erasure

The ClassLoader Subsystem

Advanced Locking: ReentrantLock and StampedLock

The Volatile Keyword and the JMM

Mastering Optional: Null Safety

Asynchronous Java: CompletableFuture

The equals() and hashCode() Contract

Designing Truly Immutable Classes

Mini Project: In-Memory Key-Value Store (Redis Clone)

Primitives, Wrappers, and Autoboxing

Control Flow and Branch Prediction

Arrays and CPU Cache Locality

Encapsulation and Access Modifiers

Polymorphism: Overloading vs Overriding

Interfaces vs Abstract Classes

ArrayList vs LinkedList Internals

HashMap Internals: Hashing, Collisions, and Treeification

Lambda Expressions and Functional Interfaces

Mini Project: Multithreaded Task Executor

Mini Project: Token Bucket Rate Limiter

Mastering OOP: Inheritance and Polymorphism

Deep Dive: The Collections Framework

Modern Java: Streams and Lambdas

Architectural Patterns: Singleton to Strategy

The Staff Engineer Interview Playbook

Introduction to Java

JVM, JDK, JRE (Deep Explanation)

Strings (Immutability & String Pool)

Memory Management (Heap, Stack, Metaspace)

Garbage Collection (G1, CMS, ZGC)

Multithreading & Concurrency Mastery

Writing Production-Grade Java

Mini Project: LRU Cache

LLD Masterclass Module 4: Advanced Behavioral Patterns

LLD Lesson: API Contract Design (REST & DTOs)

LLD Masterclass: Designing a Movie Booking System (BookMyShow)

LLD Masterclass: Designing a Multi-Level Parking Lot

LLD Masterclass: Designing a Vending Machine

LLD Masterclass Module 2: Design Patterns in Production

LLD Masterclass Module 1: Foundational LLD & SOLID Principles

LLD Masterclass: The Observer Pattern in Production Systems

LLD Lesson: The Chain of Responsibility Pattern

LLD Lesson: The Command Pattern

LLD Lesson: The Decorator Pattern

LLD Lesson: The Factory Pattern

LLD Lesson: The Strategy Pattern

LLD Schema Design: Curated Practice Problems

LLD Masterclass Module 3: Schema & API Design

The Senior Engineer Guide to LLD: SOLID Principles in Practice

Docker for Java Developers: A Production Guide to Containerization

Cgroup Awareness in Java: Avoiding OOM Kills

CPU Pipeline Stalls: Identifying Cache Misses in Java

Hardware-Aware Programming: Optimizing for Modern CPUs

Hardware-Level False Sharing: Designing High-Speed Java Objects

HikariCP Tuning: Diagnosing Database Connection Pool Exhaustion

HikariCP Tuning: The Math behind Connection Pools

Java Flight Recorder (JFR): Continuous Profiling with Zero Overhead

Java Heap Dump Analysis: A Step-by-Step Guide to Finding Memory Leaks

The Java Memory Model (JMM): Volatile, Happens-Before, and Visibility

Java Virtual Threads: High-Concurrency without the Complexity

LMAX Disruptor: How to Process 6M Transactions/Sec on One Thread

Modern Java GC: G1 vs. ZGC - Choosing the Right Collector

Zero-Copy in Netty: The Backbone of High-Speed Java Networking

Spring Boot Timeouts: The Production Guide for HTTP, DB, Redis, and Kafka

Database Connection Pool Tuning: HikariCP, PostgreSQL, and Traffic Spikes

Spring Boot Production Readiness Checklist: Timeouts, Pools, Health Checks, and Observability

Java Concurrency Patterns: CompletableFuture, Structured Concurrency, and Thread-Safe Design

Java Memory Management Deep Dive: Heap, GC, and Production Tuning

Spring Security OAuth2 and JWT: Production Implementation Guide

Scaling Spring Boot Applications to Handle 10 Million Daily Active Users

Java Profiling and Heap Analysis: Finding Memory Leaks and CPU Bottlenecks

Thread Pool Exhaustion in Spring Boot: Diagnosis, Prevention, and Recovery

Java Streams API: Advanced Patterns and Performance