Task Manager - .NET Technical Interview Exercise

A full-stack task management application built with ASP.NET Core 8 Web API, Angular 17, and PostgreSQL, following Clean Architecture principles.

Live Demo

• Frontend: https://task-manager-web-topaz.vercel.app
• Backend API: https://zestful-sparkle-production.up.railway.app

User Story

As a team member, I want to manage my tasks through a web application, So that I can create, view, update, and delete tasks while having my account secured with authentication.

Acceptance Criteria

• Users can register and log in with username/password
• Authenticated users can create tasks with a title, description, status, and due date
• Users can view all tasks (public) or filter to see only their own tasks
• Users can edit and delete their tasks
• Task status can be set to Pending, InProgress, or Completed
• The "All Tasks" view displays the owner of each task
• Unauthenticated users are redirected to the login page
• All operations are available through a responsive web interface

Architecture

This project follows Clean Architecture principles with clear separation of concerns:

TaskManager/
├── src/
│   ├── TaskManager.Domain/           # Entities, Interfaces, Exceptions (innermost)
│   ├── TaskManager.Application/      # Services, DTOs, Validation, Mapping
│   ├── TaskManager.Infrastructure/   # PostgreSQL + ADO.NET, JWT Auth, BCrypt
│   ├── TaskManager.WebAPI/           # ASP.NET Core 8 Controllers, Middleware
│   └── TaskManager.Angular/          # Angular 17 Frontend
├── tests/
│   ├── TaskManager.Domain.Tests/     # 25 tests
│   ├── TaskManager.Application.Tests/ # 88 tests
│   └── TaskManager.WebAPI.Tests/     # 33 tests
├── Dockerfile
├── PROCESS.md                        # Development thought process
└── TaskManager.sln

Dependency Flow: WebAPI -> Application -> Domain <- Infrastructure

Key Design Decisions

• No Entity Framework / Dapper / Mediator: Raw ADO.NET with Npgsql for data access, demonstrating manual SQL and parameter handling
• PostgreSQL (Neon): Serverless PostgreSQL for production; auto-scaling and zero infrastructure management
• JWT Authentication: Stateless token-based auth with BCrypt password hashing
• Clean Architecture: Domain has zero dependencies; Application depends only on Domain; Infrastructure implements Domain interfaces
• Custom Migration Runner: SQL migration files embedded as assembly resources, tracked in __MigrationHistory, executed in transactions on startup
• Standalone Components: Angular 17 standalone components (no NgModule)

Prerequisites

• .NET 8 SDK
• Node.js 18+ and npm
• Angular CLI (npm install -g @angular/cli)

Getting Started

Backend

# From the root directory
dotnet restore
dotnet build

# Run the API (database migrations run automatically)
dotnet run --project src/TaskManager.WebAPI

The API will be available at:

• HTTP: http://localhost:5000
• Swagger UI: http://localhost:5000/swagger (Development mode only)

Frontend

cd src/TaskManager.Angular

npm install
ng serve

The app will be available at http://localhost:4200

Running Tests

# Run all 146 tests
dotnet test

# Run with verbose output
dotnet test --verbosity normal

# Run specific test project
dotnet test tests/TaskManager.Domain.Tests
dotnet test tests/TaskManager.Application.Tests
dotnet test tests/TaskManager.WebAPI.Tests

Configuration

Backend configuration is in src/TaskManager.WebAPI/appsettings.json:

{
  "ConnectionStrings": {
    "DefaultConnection": "Host=...;Database=...;Username=...;Password=...;SSL Mode=Require"
  },
  "JwtSettings": {
    "SecretKey": "YourSuperSecretKeyThatIsAtLeast32CharactersLong!2024",
    "Issuer": "TaskManagerAPI",
    "Audience": "TaskManagerApp",
    "ExpirationMinutes": 60
  }
}

Seeded Data / Demo Credentials

The application seeds the following data on first run:

Demo User:

• Username: admin
• Password: Admin123!
• Email: admin@taskmanager.com

Sample Tasks:

1. "Complete project documentation" - Pending
2. "Setup continuous integration" - InProgress
3. "Review code quality" - Pending

API Endpoints

Tasks API (/api/tasks)

Method	Endpoint	Auth	Description
GET	/api/tasks	No	Get all tasks (with owner username)
GET	/api/tasks/{id}	Yes	Get task by ID
GET	/api/tasks/my	Yes	Get current user's tasks
POST	/api/tasks	Yes	Create a new task
PUT	/api/tasks/{id}	Yes	Update a task
DELETE	/api/tasks/{id}	Yes	Delete a task

Auth API (/api/auth)

Method	Endpoint	Auth	Description
POST	/api/auth/register	No	Register a new user
POST	/api/auth/login	No	Login and get JWT token
GET	/api/auth/me	Yes	Get current user info

Technology Stack

Backend:

• .NET 8 / ASP.NET Core 8 Web API
• PostgreSQL with raw ADO.NET (Npgsql)
• JWT Bearer Authentication
• BCrypt.Net for password hashing
• Global exception handling middleware
• Custom SQL migration runner

Frontend:

• Angular 17 (standalone components)
• Bootstrap 5 (responsive: table on desktop, cards on mobile)
• RxJS
• TypeScript
• Auth interceptor + route guards

Testing (146 tests):

• xUnit
• Moq
• FluentAssertions

Deployment:

• Backend: Railway (Docker)
• Frontend: Vercel
• Database: Neon (serverless PostgreSQL)