CASE STUDY 03 / OPEN-SOURCE / FULL STACK

Technical Chat — Real-Time Messaging Application

A one-to-one messaging application with persisted conversations and live delivery.

ARCHITECTURE / TECHNICAL-CHAT

CLIENTAngularConversation views
APISpring Boot · STOMPJWT · WebSocket
STORAGEMongoDBPersisted conversations

Authenticated, real-time, persisted messaging

Problem

Create a focused messaging experience with account access, a conversation directory and reliable real-time message delivery.

Architecture

A Spring Boot API handles registration, authentication, validation and persisted conversation history in MongoDB. WebSocket/STOMP carries live messages. An Angular client provides responsive conversation views.

What I Built

The application includes stateless JWT authentication, Spring Security, online and offline presence, a user directory, one-to-one conversations and structured REST and messaging error handling.

Engineering Details

The backend uses layered controllers, services, repositories, DTOs and mappers with Lombok and MapStruct. The client uses TypeScript and Angular. CORS and request validation support the browser-facing API.

Tech Stack

Java 21
Spring Boot
Spring Security
MongoDB
WebSocket / STOMP
JWT
Angular
Maven
Lombok
MapStruct
REST API
Validation
CORS

Source code

The source code for this project is public on GitHub.

View on GitHub

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