Module 1

The Java Machine

3 articles

01Why Java Is the Way It Is15 min read

03How Java Actually Runs15 min read

04Why Only One Public Class Per File10 min read

Module 2

Object-Oriented Design & Type System

4 articles

02Object-Oriented Programming: The Four Pillars20 min read

05Primitives, Two's Complement and Type Casting20 min read

06IEEE 754: Why 0.1 + 0.2 Is Not 0.3 in Java15 min read

07Reference Types, String Pool and Wrappers20 min read

Module 3

Methods, Constructors & Memory

3 articles

08Methods, Access Modifiers and Varargs15 min read

09Constructors In Depth20 min read

10Memory Management and Garbage Collection25 min read

Module 4

Class Design Patterns & Abstractions

7 articles

11Concrete, Abstract, Object, and Nested Classes: The Complete Guide30 min read

12Generics, Type Erasure and Wildcards25 min read

13POJO, Enum, and Final Classes: Advanced Architecture & JVM Mechanics20 min read

14Singleton and Immutable Classes: Design Patterns & JVM Concurrency25 min read

15Interfaces In Depth20 min read

16Default, Static and Private Interface Methods15 min read

17Functional Interfaces and Lambda Expressions20 min read

Module 5

Metaprogramming & Error Handling

5 articles

18Reflection In Depth15 min read

19Annotations15 min read

20Exception Handling20 min read

21Operators15 min read

22Control Flow Statements15 min read

Module 6

The Collections Framework

6 articles

23Collections Framework: Architecture, Hierarchy & Iteration25 min read

24Queue, PriorityQueue, Comparator vs Comparable20 min read

25Deque and the List Family20 min read

26HashMap Internal Working: The Complete Low-Level Guide30 min read

27LinkedHashMap and TreeMap: When Order Matters20 min read

28The Set Family: HashSet, LinkedHashSet & TreeSet15 min read

Module 7

Streams & Functional Pipelines

1 articles

29Java 8 Streams: Pipelines, Laziness & Parallelism25 min read

Module 8

Concurrency & Multithreading

10 articles

30Threads, Processes and Their Memory Model20 min read

31Thread Creation, Lifecycle, Monitor Locks & wait/notify25 min read

32Thread Coordination: join, Daemon Threads, Priority & Deprecated Methods20 min read

33Explicit Locks: ReentrantLock, ReadWriteLock, StampedLock, Semaphore & Condition30 min read

34Lock-Free Concurrency: CAS, Atomic Classes & volatile25 min read

35ThreadPoolExecutor: Architecture, Task Flow & Sizing30 min read

36Asynchronous Programming: Future, Callable & CompletableFuture25 min read

37Executors Factory Pools, ForkJoinPool & Work Stealing25 min read

38ScheduledThreadPoolExecutor: Periodic Tasks & Time Triggers20 min read

39ThreadLocal and Virtual Threads (Project Loom)25 min read

Module 9

Productivity & Developer Tooling

2 articles

40Project Lombok: Top 10 Features & Compile-Time Code Generation15 min read

41Optional: Java 8 to 11 All Methods, Patterns & Antipatterns20 min read

Module 10

High-Performance I/O & NIO

4 articles

42Traditional File Handling: Streams as a Decorator Pattern20 min read

43Java NIO Deep Dive: 5 Advantages Over Traditional I/O20 min read

44Java NIO Buffer Internals: position, limit, capacity & compact25 min read

45FileChannel & Zero-Copy Transfers20 min read

Module 11

Modern Java Evolution (Java 14–21)

7 articles

46Java 14: Switch Expressions & Arrow Syntax15 min read

47Java 15: Text Blocks & Multi-Line Strings15 min read

48Java 16: Pattern Matching for instanceof15 min read

49Java 16: Records (Immutable Data Carriers)20 min read

50Java 17: Sealed Classes and Interfaces20 min read

51Java 21: Pattern Matching for switch20 min read

52Java 21: Sequenced Collections (Unified First/Last Access)15 min read