Kotlin

Kotlin

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Section 1: Getting Started

3Lessons ·
- 1: Setting Up Kotlin and the Toolchain
  
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- 2: Kotlin vs Java: Key Differences
  
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- 3: Running Kotlin Scripts vs Compiled Programs
  
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Section 2: Core Syntax

8Lessons ·
- 4: Variables: val and var
  
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- 5: Types and Type Inference
  
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- 6: Control Flow Statements
  
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- 7: When Expressions
  
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- 8: Ranges and Progressions
  
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- 9: Functions and Default Arguments
  
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- 10: Named Arguments
  
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- 11: String Templates
  
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Section 3: Null Safety

5Lessons ·
- 12: Nullable Types
  
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- 13: Safe Calls and the Elvis Operator
  
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- 14: The !! Operator and Its Risks
  
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- 15: Platform Types and Java Interop
  
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- 16: Smart Casts
  
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Section 4: Object-Oriented Kotlin

8Lessons ·
- 17: Classes and Constructors
  
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- 18: Primary and Secondary Constructors
  
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- 19: Data Classes
  
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- 20: Inheritance and Interfaces
  
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- 21: Sealed Classes and Sealed Interfaces
  
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- 22: Object Declarations and Companion Objects
  
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- 23: Visibility Modifiers
  
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- 24: Delegation with by
  
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Section 5: Functional Kotlin

6Lessons ·
- 25: Lambda Expressions and Higher-Order Functions
  
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- 26: Extension Functions
  
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- 27: Extension Properties
  
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- 28: Collections and Sequence Operations
  
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- 29: Scope Functions: let, run, apply, also, with
  
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- 30: Inline Functions and Reified Types
  
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Section 6: Coroutines

7Lessons ·
- 31: Introduction to Coroutines
  
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- 32: Suspend Functions
  
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- 33: Coroutine Builders: launch and async
  
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- 34: Coroutine Scopes and Structured Concurrency
  
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- 35: Flow for Asynchronous Streams
  
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- 36: StateFlow and SharedFlow
  
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- 37: Exception Handling in Coroutines
  
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Section 7: Collections Deep Dive

5Lessons ·
- 38: List, Set, and Map Operations
  
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- 39: Immutable vs Mutable Collections
  
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- 40: Sequences vs Collections: Lazy Evaluation
  
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- 41: Grouping, Chunking, and Windowed Operations
  
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- 42: Destructuring Declarations
  
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Section 8: Type System Deep Dive

5Lessons ·
- 43: Type Aliases
  
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- 44: Variance: in and out
  
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- 45: Inline Value Classes
  
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- 46: Reified Generics in Practice
  
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- 47: Contracts for Smart Compiler Analysis
  
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Section 9: Interop and Tooling

4Lessons ·
- 48: Calling Java from Kotlin and Vice Versa
  
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- 49: Building with Gradle Kotlin DSL
  
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- 50: Testing Kotlin Code with Kotest
  
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- 51: Kotlin Multiplatform Basics
  
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Section 10: Kotlin DSLs and Patterns

4Lessons ·
- 52: Kotlin DSLs and Builder Patterns
  
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- 53: Property Delegation with by lazy and Delegates.observable
  
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- 54: Annotations in Kotlin
  
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- 55: Kotlin Symbol Processing (KSP) Basics
  
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Section 11: Testing and Quality

4Lessons ·
- 56: Unit Testing with JUnit in Kotlin
  
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- 57: Mocking with MockK
  
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- 58: Property-Based Testing Concepts
  
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- 59: Static Analysis with Detekt
  
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Section 12: Server-Side Kotlin

3Lessons ·
- 60: Building APIs with Ktor
  
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- 61: Building APIs with Spring Boot and Kotlin
  
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- 62: Database Access with Exposed
  
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Section 13: Practical Projects

5Lessons ·
- 63: Building a Command-Line Application in Kotlin
  
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- 64: Building a Simple REST Client with Coroutines
  
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- 65: Building a Small Ktor Web Service
  
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- 66: Building a Task Manager with Coroutines and Flow
  
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- 67: Building a Kotlin DSL for Configuration
  
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Section 14: Interview Practice

3Lessons ·
- 68: Common Kotlin Interview Questions on Null Safety
  
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- 69: Common Kotlin Interview Questions on Coroutines
  
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- 70: Comparing Kotlin Idioms to Java Equivalents
  
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Section 15: More Practice Exercises

4Lessons ·
- 71: Practice Exercise: Building a Class-Based To-Do List
  
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- 72: Practice Exercise: Building a Coroutine-Based Data Fetcher
  
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- 73: Practice Exercise: Building a Simple DSL for HTML Generation
  
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- 74: Practice Exercise: Refactoring Java Code Idiomatically into Kotlin
  
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Section 16: More Standard Library

4Lessons ·
- 75: Working with Strings in Kotlin
  
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- 76: Working with Regular Expressions in Kotlin
  
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- 77: The Result Type for Error Handling
  
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- 78: Working with Dates and Times in Kotlin
  
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Section 17: Multiplatform Kotlin

3Lessons ·
- 79: Kotlin Multiplatform Architecture Overview
  
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- 80: Expect/Actual Declarations
  
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- 81: Sharing Business Logic Across Platforms
  
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Section 18: kotlin.collections In Depth

6Lessons ·
- 82: List Operations: map, filter, fold In Depth
  
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- 83: Set Operations: union, intersect, subtract
  
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- 84: Map Operations: mapValues, mapKeys, filterValues
  
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- 85: MutableList vs List Semantics
  
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- 86: Sequences vs Collections Performance
  
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- 87: zipWithNext and associateBy
  
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Section 19: kotlin.text In Depth

4Lessons ·
- 88: String Templates and Raw Strings
  
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- 89: String Extension Functions: trim, padStart, chunked
  
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- 90: Regex in Kotlin
  
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- 91: StringBuilder Usage in Kotlin
  
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Section 20: kotlin.ranges and kotlin.sequences

4Lessons ·
- 92: Range Expressions and step
  
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- 93: IntRange, CharRange, and Progressions
  
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- 94: Building Lazy Sequences
  
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- 95: Infinite Sequences with generateSequence
  
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Section 21: kotlin.io and File Handling

3Lessons ·
- 96: Reading Files with kotlin.io Extensions
  
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- 97: Writing Files in Kotlin
  
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- 98: Working with Path and File APIs
  
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Section 22: kotlinx.coroutines Deep Dive

7Lessons ·
- 99: Dispatchers: Main, IO, Default, Unconfined
  
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- 100: CoroutineContext and Job Hierarchy
  
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- 101: SupervisorJob and Exception Propagation
  
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- 102: Channels for Coroutine Communication
  
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- 103: select Expression for Coroutines
  
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- 104: Testing Coroutines with runTest
  
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- 105: Coroutine Exception Handlers In Depth
  
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Section 23: kotlin.reflect

3Lessons ·
- 106: KClass and Runtime Type Information
  
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- 107: Reflecting Over Properties and Functions
  
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- 108: Annotation Processing with KSP Revisited
  
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Section 24: Android Development with Kotlin Overview

3Lessons ·
- 109: Kotlin-Specific Android Patterns
  
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- 110: ViewModel and LiveData in Kotlin
  
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- 111: Jetpack Compose State Management Basics
  
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Section 25: Kotlin Multiplatform Deep Dive

5Lessons ·
- 112: Setting Up a KMP Project Structure
  
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- 113: Sharing UI with Compose Multiplatform
  
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- 114: Platform-Specific Implementations with expect/actual
  
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- 115: Publishing a KMP Library
  
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- 116: Testing Shared KMP Code
  
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Section 26: Kotlin for Backend Deep Dive

6Lessons ·
- 117: Ktor Routing In Depth
  
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- 118: Ktor Authentication Plugins
  
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- 119: Ktor Content Negotiation and Serialization
  
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- 120: Exposed ORM Transactions
  
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- 121: Building a GraphQL Server with Kotlin
  
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- 122: Rate Limiting and Caching in Ktor
  
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Section 27: Kotlin Design Patterns

6Lessons ·
- 123: The Builder Pattern with Kotlin DSLs
  
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- 124: The Repository Pattern in Kotlin
  
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- 125: The Observer Pattern with Flow
  
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- 126: Dependency Injection with Koin
  
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- 127: Dependency Injection with Dagger/Hilt
  
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- 128: The Adapter Pattern in Kotlin
  
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Section 28: Advanced Language Features

7Lessons ·
- 129: Operator Overloading in Kotlin
  
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- 130: Infix Functions
  
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- 131: Tailrec Functions
  
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- 132: Multiple Return Values with Destructuring
  
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- 133: Companion Object Factory Patterns
  
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- 134: Value Classes and Inline Classes Revisited
  
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- 135: Contracts for Compiler Smart-Casting
  
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Section 29: More Practice Exercises

4Lessons ·
- 136: Practice Exercise: Building a Coroutine-Based Rate Limiter
  
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- 137: Practice Exercise: Building a Custom Kotlin DSL for HTML
  
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- 138: Practice Exercise: Building a Type-Safe Builder for API Requests
  
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- 139: Practice Exercise: Implementing a Simple State Machine with Sealed Classes
  
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Section 30: More Interview Practice

4Lessons ·
- 140: Common Kotlin Interview Questions on Sealed Classes
  
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- 141: Common Kotlin Interview Questions on Inline Functions
  
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- 142: Whiteboard Practice: Implementing a Linked List in Kotlin
  
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- 143: Timed Mock Assessment on Core Kotlin
  
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Section 31: Kotlin Type System Deep Dive

6Lessons ·
- 144: Nothing Type and Its Uses
  
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- 145: Unit Type vs Void
  
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- 146: Star Projections in Generics
  
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- 147: Definitely Non-Nullable Types
  
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- 148: Type Aliases for Complex Generics
  
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- 149: Function Types and Higher-Order Type Signatures
  
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Section 32: Kotlin Null Safety Advanced

4Lessons ·
- 150: Nullability Annotations for Java Interop
  
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- 151: Handling Platform Types Safely
  
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- 152: Late-Initialized Properties (lateinit)
  
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- 153: Null Safety in Collections
  
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Section 33: Kotlin Testing Deep Dive

5Lessons ·
- 154: Behavior-Driven Testing with Kotest Specs
  
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- 155: Mocking with MockK In Depth
  
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- 156: Parameterized Tests in Kotlin
  
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- 157: Testing Android ViewModels
  
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- 158: Contract Testing Basics in Kotlin
  
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Section 34: Kotlin Build Tooling Deep Dive

4Lessons ·
- 159: Gradle Kotlin DSL Convention Plugins
  
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- 160: Version Catalogs in Gradle
  
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- 161: Multi-Module Project Configuration
  
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- 162: Kotlin Compiler Plugins Overview
  
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Section 35: Kotlin Serialization

4Lessons ·
- 163: kotlinx.serialization Basics
  
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- 164: Custom Serializers
  
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- 165: Polymorphic Serialization
  
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- 166: Serializing to Protocol Buffers with Kotlin
  
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Section 36: Kotlin Performance Considerations

5Lessons ·
- 167: Inline Functions and Performance
  
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- 168: Avoiding Boxing with Primitive Arrays
  
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- 169: Collection Performance Characteristics
  
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- 170: Coroutine Performance Best Practices
  
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- 171: Benchmarking Kotlin Code with JMH
  
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Section 37: Kotlin Native Overview

4Lessons ·
- 172: Kotlin/Native Architecture
  
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- 173: Interop with C Libraries in Kotlin/Native
  
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- 174: Memory Management in Kotlin/Native
  
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- 175: Deploying Kotlin/Native Executables
  
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Section 38: Kotlin for Data and Scripting

4Lessons ·
- 176: Kotlin Scripting (.kts files)
  
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- 177: Using Kotlin for Data Analysis with Kotlin DataFrame
  
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- 178: Kotlin Notebook Basics
  
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- 179: Building Custom Gradle Tasks with Kotlin Scripting
  
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Section 39: More Coroutines Practice

5Lessons ·
- 180: Practice Exercise: Building a Coroutine-Based Download Manager
  
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- 181: Structured Concurrency Pitfalls and How to Avoid Them
  
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- 182: Cold vs Hot Flows
  
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- 183: StateFlow vs SharedFlow Use Cases Revisited
  
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- 184: Flow Operators: debounce, distinctUntilChanged, flatMapLatest
  
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Section 40: More Android-Adjacent Patterns

4Lessons ·
- 185: MVI Architecture Pattern in Kotlin
  
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- 186: Unidirectional Data Flow Concepts
  
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- 187: Navigation Component with Kotlin
  
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- 188: WorkManager for Background Tasks
  
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Section 41: More Practical Projects

5Lessons ·
- 189: Building a Command-Line Weather App with Coroutines
  
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- 190: Building a Simple Note-Taking App with Ktor Backend
  
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- 191: Building a Kotlin Multiplatform Calculator
  
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- 192: Building a Simple Chat Application with WebSockets in Ktor
  
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- 193: Building a REST API with Authentication in Ktor
  
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Section 42: More Design and Architecture Practice

4Lessons ·
- 194: Clean Architecture in Kotlin Projects
  
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- 195: Practice Exercise: Refactoring to Use Sealed Classes for State
  
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- 196: Practice Exercise: Building a Type-Safe Navigation Graph
  
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- 197: Practice Exercise: Implementing the Repository Pattern with Coroutines
  
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Section 43: Kotlin Language Evolution

4Lessons ·
- 198: What's New in Recent Kotlin Versions
  
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- 199: K2 Compiler Overview
  
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- 200: Context Receivers (Experimental Feature)
  
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- 201: Kotlin Symbol Processing Evolution
  
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Section 44: More Interview and Review

8Lessons ·
- 202: Common Kotlin Interview Questions on Coroutines vs Threads
  
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- 203: Common Kotlin Interview Questions on Data Classes
  
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- 204: Common Kotlin Interview Questions on Extension Functions
  
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- 205: Whiteboard Practice: Implementing a Debounce Function with Coroutines
  
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- 206: Code Review Checklist for Idiomatic Kotlin
  
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- 207: Common Kotlin Interview Questions on Generics and Variance
  
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- 208: Common Kotlin Interview Questions on Scope Functions
  
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- 209: Interview Practice: System Design Basics for Kotlin Backend Roles
  
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Section 45: Kotlin Delegation Patterns Deep Dive

4Lessons ·
- 210: Class Delegation with the by Keyword In Depth
  
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- 211: Property Delegation: Custom Delegate Classes
  
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- 212: Map-Backed Property Delegation
  
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- 213: vetoable and observable Delegates In Depth
  
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Section 46: Kotlin Annotations Deep Dive

4Lessons ·
- 214: Built-In Annotations: @JvmStatic, @JvmOverloads, @JvmName
  
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- 215: Meta-Annotations and Annotation Targets
  
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- 216: Retention Policies for Custom Annotations
  
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- 217: Building a Custom Annotation Processor
  
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Section 47: Kotlin for Gradle Plugin Development

3Lessons ·
- 218: Writing a Custom Gradle Plugin in Kotlin
  
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- 219: Testing Gradle Plugins
  
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- 220: Publishing Gradle Plugins to the Portal
  
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Section 48: Kotlin Concurrency Beyond Coroutines

3Lessons ·
- 221: Java Concurrency Utilities from Kotlin
  
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- 222: Atomic Types from Kotlin
  
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- 223: Thread-Safe Singleton Patterns in Kotlin
  
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Section 49: Kotlin Compiler Internals

4Lessons ·
- 224: How Kotlin Compiles to JVM Bytecode
  
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- 225: Understanding Kotlin's Null Checks at Bytecode Level
  
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- 226: Inline Function Bytecode Generation
  
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- 227: Debugging Kotlin Coroutines with the Debugger
  
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Section 50: Real-World Kotlin Case Studies

4Lessons ·
- 228: Migrating a Java Codebase to Kotlin Incrementally
  
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- 229: Common Java-to-Kotlin Interop Pitfalls
  
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- 230: Kotlin Style Guide and Ktlint
  
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- 231: Performance Tuning a Large Kotlin Codebase
  
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Section 51: Final Practice Projects

6Lessons ·
- 232: Building a Personal Finance Tracker with Ktor and Exposed
  
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- 233: Building a Multiplatform To-Do App
  
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- 234: Building a Simple Job Scheduler with Coroutines
  
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- 235: Building a Rate-Limited API Client with Retry Logic
  
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- 236: Building a Real-Time Chat App with Ktor WebSockets and Compose
  
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- 237: Building a Podcast Downloader CLI with Coroutines
  
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Section 52: Kotlin for Server-Side Reactive Programming

4Lessons ·
- 238: Reactive Streams with Kotlin Flow and WebFlux
  
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- 239: Backpressure Handling in Flow
  
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- 240: Combining Multiple Flows: zip, combine, merge
  
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- 241: Testing Reactive Flows End to End
  
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Section 53: More Practice and Drills

5Lessons ·
- 242: Practice Exercise: Building a Kotlin-Based Configuration DSL
  
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- 243: Practice Exercise: Implementing a Custom Collection Type
  
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- 244: Practice Exercise: Building a Simple Dependency Graph Resolver
  
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- 245: Practice Exercise: Building a Simple Event Sourcing System
  
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- 246: Practice Exercise: Building a Type-Safe SQL Query Builder
  
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Section 54: Kotlin Security Practices

4Lessons ·
- 247: Secure Coding Practices in Kotlin
  
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- 248: Handling Secrets in Kotlin Applications
  
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- 249: Input Validation Patterns in Kotlin
  
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- 250: Preventing Injection Attacks in Kotlin Backends
  
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