# Architecture Layers

#### Frontend Architecture

The application uses the Next.js App Router with the following structure:

```
app/
├── (auth)/         # Auth routes (login, register)
├── (protected)/    # Protected routes
├── dashboard/      # Dashboard features
├── clients/        # Client management
├── invoices/       # Invoice management
├── products/       # Product management
└── settings/       # User settings
```

The frontend leverages modern development practices like component-based architecture, React Context, and custom hooks to manage state efficiently.

#### Backend Services

The platform uses Supabase for backend services, including:

* Authentication & Authorization with JWT and OAuth integration.
* Real-time Database with subscriptions for live updates.
* Row Level Security for granular access control and policy-based data access.
* Storage for managing user-uploaded documents.

#### Database Structure

The system is built around core tables that support key features:

* clients – stores client data.
* invoice\_companies – stores companies related to invoices.
* invoices – contains invoice details.
* invoice\_items – line items for each invoice.
* product\_lines – product catalog for invoices.

#### APIs

APIs are implemented via Supabase Client for:

* Auth API – managing user authentication.
* Database API – querying and managing the database.
* Real-time Subscriptions – enabling live updates.
* Storage API – uploading and retrieving files.

#### Infrastructure

**Deployment Architecture**

* Frontend: Hosted on Netlify for static site generation.
* Backend: Deployed on Supabase Cloud.
* Database: Powered by Supabase Postgres with RLS for enhanced security.

#### Security Measures

The platform employs robust security mechanisms:

**Authentication**

* JWT-based authentication.
* OAuth integration with providers like Google.

**Authorization**

* Row Level Security (RLS) policies for access control.
* User-scoped data access.

**Data Protection**

* Input validation using Zod.
* Type safety with TypeScript.
* Prepared statements to prevent SQL injection.

#### Scalability Considerations

**Frontend**

* Static page generation for improved performance.
* Code splitting and dynamic imports for faster loading.

**Backend**

* Efficient Row Level Security policies.
* Indexed queries to optimize database performance.
* Connection pooling for high concurrency support.

#### Technical Specifications

**Programming Languages**

* TypeScript for frontend and backend logic.
* SQL (PostgreSQL) for database queries.
* CSS (Tailwind) for styling.

**Core Dependencies**

Key libraries and tools used in the platform include:

{ "next": "14.1.0", "react": "18.2.0", "typescript": "5.3.3", "@supabase/auth-helpers-nextjs": "0.9.0", "@react-pdf/renderer": "3.1.14", "tailwindcss": "3.4.1", "i18next": "23.10.0" }

#### Development Tools

* Package Manager: npm
* Build Tool: Next.js built-in
* Type Checking: TypeScript
* Linting: ESLint
* Formatting: Prettier

#### Version Control Strategy

The project follows modern version control practices:

* Feature-based branching for parallel development
* Conventional commits for meaningful and consistent commit messages
* Semantic versioning for clear release management
* Environment-based configuration for deployment flexibility
