🧩 CustomCADs — Backend

CustomCADs is the backend powering a full-featured platform for discovering, purchasing, and commissioning 3D CAD models.
It’s built as a Modular Monolith following Clean Architecture, DDD, CQRS, and EDA principles — combining structure, flexibility, and scalability in one cohesive system.

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🏗️ Architecture & Design

• Runtime: Latest .NET (currently 9)
• Architecture: Modular Monolith with per-module Clean Architecture and Shared Kernel
  • Domains adhere to DDD
  • Application layers follow CQRS
  • Cross-module and async flows rely on EDA
  • Sagas orchestrate complex processes (deliveries, payments, rewards, etc.)
• Cloud:
  • Cloudflare R2 → CADs & images storage
  • AWS → EC2/EB + ECR (backend), RDS (PostgreSQL), ACM + CloudFront (HTTPS/CDN)
  • Namecheap → domain management
• DevOps:
  • GitHub Actions → CI/CD (build → push → manual deploy)
  • Docker → image packaging and deploys
  • Terraform → full Infrastructure as Code (IaC)
• Solutions:
  • CustomCADs.sln (Development)
  • CustomCADs.Staging.sln
  • CustomCADs.Production.sln
  • Root also includes GitHub workflows, Terraform configs, Dockerfiles, and Bash automation scripts.

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🧰 Core Libraries

Layer	Technologies
API	FastEndpoints · Microsoft.OpenAPI · Scalar
Infrastructure	Polly · Stripe · SignalR · WolverineFx · FluentValidation · FluentEmail · Quartz.NET
Persistence	PostgreSQL · EF Core · EFCore.BulkExtensions

🧑‍💻 Developer Utilities

• Custom Bash scripts for EF Core CLI automation on Linux
• Optional source generation for Wolverine message handlers
• Dedicated EF Core migration project for all modules (instant & parallel) and a separate one for Identity

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🔐 Authentication & Core Features

• JWT + Refresh Token auth system with CSRF protection
• Google SSO via OpenID Connect
• ASP.NET Core Identity as the underlying foundation
• Automatic request idempotency via custom middleware & attributes
• Real-time updates & notifications using SignalR
• Stripe integration (webhooks + checkout + internal reconciliation)
• Exchange rates auto-updated every 24h (cached + cron job)

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🧭 Roles & Capabilities

👤 Guests

• Register/Login
• Explore the Gallery
• Access current Exchange Rates

💼 Customers

• Manage current Cart & Items (add/remove/customize)
• Purchase Cart (persisted as one of many “Purchased Cart”)
• Request Custom 3D Models (Customs)
• Track Shipments (for purchased/delivered items or Customs)
• View Notifications

🧱 Contributors

• Upload & manage Products (CRUD)
• Submit Products for Designer validation
• Sell full rights to Products to Designers
• Apply for Designer position

🎨 Designers

• Upload Products directly to Gallery (tagged Professional)
• Validate or report Contributors’ Products
• Manage Custom Requests (accept → begin → finish)
• Purchase rights to Contributors’ Products

🛡️ Admins

• Read all resources (including Users/Roles)
• Modify most resources
• Manage Tags & Categories
• Handle reports and remove flagged content

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📂 Directory Structure

Root layout: CustomCADs/ ├── src/ │ ├── Modules/ │ ├── Shared/ │ ├── Tools/ │ └── Presentation/ ├── tests/ │ └── UnitTests/ ├── .github/ ├── .terraform/ ├── .platform/ ├── Dockerfile.dev ├── Dockerfile.staging ├── Dockerfile.production └── README.md

Src layout: src/ ├── Modules/ ├── Shared/ │ ├── Domain/ │ ├── Persistence/ │ ├── Application/ │ ├── Infrastructure/ │ └── API/ ├── Tools/ │ ├── Migrations/ │ ├── Identity/ │ └── CodeGen/ ├── Presentation/ │ ├── GlobalExceptionHandler.cs │ ├── ProgramExtensions.cs │ └── Program.cs

Modules layout: Modules/ ├── Accounts/ │ ├── Domain/ │ ├── Persistence/ │ ├── Application/ │ ├── Infrastructure/ │ └── API/ ├── Carts/ ├── Catalog/ ├── Customs/ ├── Delivery/ ├── Files/ ├── Idempotency/ ├── Identity/ ├── Notifications/ └── Printing/

Tests layout: UnitTests/ ├── Accounts/ │ ├── Data/ │ ├── Domain/ │ ├── Application/ ├── Carts/ ├── Catalog/ ├── Customs/ ├── Delivery/ ├── Files/ ├── Idempotency/ ├── Identity/ ├── Notifications/ └── Printing/

📞 Contact

• Author: Ivan (NinjataWRLD)
• Role: Co-Founder, Architect & Full-Stack/DevOps Engineer of CustomCADs
• Email: Personal or Support
• Phone: [+359 885 440 400]
• GitHub: github.com/NinjataWRLD