Code: Kotlin

Lambdas & it

Trailing braces, implicit it, and method references

String Templates

Dollar signs, curly blocks, and raw strings

Generics & Variance

Angle brackets, out projections, and :: references

Ranges & Progressions

Double-dot ranges, until, downTo, and step

Checkpoint: Symbol Fluency

Every Kotlin glyph cluster from this module in one longer drill

Keywords

Kotlin reserved words

Declarations

val, var, and explicit types

Data Classes & copy

Default arguments, copy(), and destructuring

when & Sealed Hierarchies

Exhaustive branches over sealed interfaces

Idiomatic Patterns

Scope functions and null-safe one-liners

Collection Operators

associateBy, groupBy, partition, and friends

Checkpoint: Keywords & Idioms

A custom Iterable mixing this module's material

Control Flow

when branches and loops

Functions & Methods

Default arguments, expression bodies, and suspend

Sealed Result Types

Modelling success, failure, and pending states

Exceptions & runCatching

require, custom exceptions, and Result chaining

Extension Functions

Extending types you do not own

Realistic Snippet

Coroutine API client with a sealed load state

Coroutines & Flow

flow builders, operators, and structured concurrency

Checkpoint: Real Snippets

Data classes, operators, and formatting in one pass

Speed Run: Config Loader

A key=value parser typed end to end without stopping

Speed Run: Collection Pipeline

filter-sort-sumOf chains at full pace

Speed Run: State Machine

Enum transitions through when over pairs

Speed Run: Builder DSL

apply, receivers, and a typesafe request builder

Speed Run: Tests & Asserts

A slugify function plus its kotlin.test suite

Checkpoint: Sustained Speed

An event-latency report typed in one continuous run

Assessment Sim 1: Cached Repository

A complete caching layer over a suspend repository

Assessment Sim 2: Temperature Stats

A full stdin-to-summary program

Assessment Sim 3: RPN Calculator

A complete stack evaluator with error paths

Assessment Sim 4: Inventory Ledger

A full stock-movement program with rejections

Checkpoint: Kotlin Mastery Final

A ranked traffic report -- the course's graded final