Note to Recruiters: This repository is a fork of an engineering thesis project co-created with a frontend developer. This fork serves as a portfolio showcase for the Backend Architecture, Cloud Infrastructure, and DevOps pipelines, which were designed and implemented entirely by me.
RentCarX is a cloud-native Vehicle Reservation Platform designed for scalability and maintainability. The system handles the complete rental lifecycle: from vehicle searching and booking, through secure payments, to administrative management and reporting.
The core objective was to build a robust, distributed system using Clean Architecture principles, capable of handling high traffic loads verified by Azure Load Testing.
As the Backend Architect & DevOps Engineer, I was responsible for:
- Core Architecture: Designing the system using Clean Architecture and CQRS (Command Query Responsibility Segregation) pattern with MediatR.
- Cloud Infrastructure: Deploying the solution to Azure App Service and Azure Container Apps using Docker containers.
- Observability: Implementing a full telemetry stack with OpenTelemetry, Grafana, and Prometheus for real-time monitoring.
- Background Processing: Decoupling long-running tasks (e.g., reservation deadlines, email notifications) using Hangfire workers.
- Integrations: Implementing secure payments via Stripe API and PDF/Excel reporting using QuestPDF/ClosedXML.
The solution is split into loosely coupled layers to ensure testability and separation of concerns:
| Layer | Technologies & Patterns |
|---|---|
| Presentation | ASP.NET Core Web API, Global Exception Handling, Swagger Versioning |
| Application | CQRS (MediatR), FluentValidation, DTOs, AutoMapper |
| Domain | Enterprise logic, Entities, Enums, Custom Exceptions |
| Infrastructure | EF Core, SQL Server, Identity, External Services (Stripe, Azure Blobs) |
- CQRS: Separated read and write operations to optimize performance and scalability.
- Background Jobs: Utilized a separate
RentCarX.HangfireWorkerservice to handle recurring tasks like checking car availability without blocking the main API thread. - Feature Flags: Implemented feature management to toggle system capabilities (e.g., Notification Service) dynamically.
- Language: C# (.NET 8)
- Frameworks: ASP.NET Core Web API, Entity Framework Core
- Database: Azure SQL Database / MSSQL (Dev)
- Cloud & DevOps: Azure App Service, Docker, Azure Container Registry
- Observability: OpenTelemetry, Grafana, Prometheus, Serilog
- Background Jobs: Hangfire (Persistent storage in SQL)
- Payment Gateway: Stripe API
- Reporting: QuestPDF, ClosedXML
The project is fully containerized. To spin up the backend, database, and background worker locally:
-
Clone the repository:
git clone [https://github.com/your-username/RentCarX.git](https://github.com/your-username/RentCarX.git) cd RentCarX -
Configure Environment: Rename
.env.templateto.envand fill in the necessary secrets (Stripe keys, Connection Strings). -
Run with Docker Compose:
docker-compose up -d --build
This starts the API, SQL Server, and Hangfire Dashboard.
-
Access Dashboards:
- Swagger API:
http://localhost:8080/swagger - Hangfire Dashboard:
http://localhost:8080/hangfire
- Swagger API:
- Backend Architecture & DevOps: Mikołaj Kocik
- Frontend Development: Dawid Majchrzak
This project was developed as part of an Engineering Thesis.