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Mohamed

CRM & Billing System – Internship Project

Billzard – Full Stack CRM & Billing Platform

Overview

Billzard is a powerful CRM and billing platform designed to streamline the financial and client management operations for Moroccan SMEs. Developed during my internship at M5 Tech Agency, the solution allows users to manage delivery notes (BLs), quotes (devis), invoices (factures), credit notes (avoirs), and client data , all in one centralized system.

This platform offers a mobile-first and scalable experience, reducing administrative overhead for accountants and small business owners through automation and intuitive design.

🚧 The Challenge

Businesses struggled with:

  • Manual, paper-based invoicing that slowed operations.
  • No centralized view of client activity, payments, or billing history.
  • Lack of tools to handle TVA declarations and document transitions (BL ➝ Devis ➝ Facture ➝ Avoir).
  • Poor mobile usability and inconsistent interfaces across web and mobile platforms.

🔧 My Contributions :

✅ Frontend Development

  • Built dynamic, reusable UI components in React.js using TypeScript and Tailwind CSS.
  • Developed clean, responsive views for listing, creating, and modifying:
    • Bons de Livraison (BL)
    • Devis (Quotes)
    • Factures (Invoices)
    • Factures d'avoir (Credit notes)
    • Client records

Here are some screenshots of the Frontend:

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✅ Mobile App Development (Flutter)

  • Built the mobile version of Billzard with Flutter, supporting both light and dark modes.
  • Replicated full platform functionality on mobile: billing, quote creation, client management, invoice transfers.
  • Implemented stateful, reactive UIs tailored for accountants and field agents using Android devices.

Here are some screenshots of the Mobile App:

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✅ Backend Development (ASP.NET Core API)

  • Developed RESTful APIs for all billing modules, ensuring secure CRUD operations.
  • Created endpoints to handle:
    • Creation, deletion, and transfer of billing documents
    • Client-specific data retrieval and updates
  • Used Swagger for testing and documenting endpoints.

Here are some screenshots from Swagger :

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✅ Database Engineering (SQL Server)

  • Designed stored procedures to improve backend security and consistency:
    • Insert client + invoice + line items in a single transaction
    • Transfer invoice to credit note with validation
    • Ensure atomic operations across financial records

Here are some screenshots from SQL Server :

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Tech Stack

Frontend

React.js
TypeScript
Tailwind CSS

Mobile

Flutter

Backend

ASP.NET Core

Database

SQL Server (Stored Procedures, Triggers)

Version Control

Git

Testing & API Docs

Swagger

Project Management

Trello

Impact & Outcome

  • Successfully delivered a working CRM prototype used for internal client demos at M5 Tech Agency
  • Reduced invoice creation time by streamlining the document lifecycle and automating key financial logic
  • Gained advanced hands-on experience in full stack development across web, mobile, API, and database layers.
  • Extended contributions beyond the internship period due to strong performance and platform ownership.