A complete, step-by-step Ktor backend tutorial series. Build REST APIs, connect databases, handle file uploads, and secure your endpoints with JWT — all in Kotlin.

Build a production-ready backend with the Kotlin you already know.


Part 1: Getting Started

#TutorialWhat You Will Learn
1What is Ktor?What Ktor is, why use it, Ktor vs Express/FastAPI/Spring Boot
2Ktor vs Spring BootFeature comparison, performance, when to use each
3Project SetupProject structure, plugins, configuration, error handling

Part 2: Building the API

#TutorialWhat You Will Learn
4RoutingGET/POST/PUT/DELETE, path params, query params, route grouping
5SerializationJSON with kotlinx.serialization, request/response DTOs
6Database SetupExposed ORM, H2, table definitions, coroutine-safe queries
7CRUD OperationsFull REST API, repository pattern, validation, status codes

Part 3: Advanced Features

#TutorialWhat You Will Learn
8RelationshipsOne-to-many, many-to-many, JOIN queries, filtering, sorting
9File UploadsMultipart form data, static files, upload validation
10Database MigrationsFlyway setup, versioned SQL migrations, schema management
11JWT AuthenticationJWT tokens, bcrypt, protected routes, register/login

Prerequisites

Source Code

All source code is available on GitHub with one branch per tutorial:

github.com/kemalcodes/ktor-tutorial