DocuGen Pro

The Problem

In many business environments, the manual creation of professional documents—such as contracts, certificates, and invoices—is highly time-consuming and prone to human error. While template-based solutions exist, they often lack the necessary flexibility to adapt to the highly specific, dynamic needs of different companies.

There was a clear need for an intelligent system that could not only generate templates on the fly but also seamlessly convert them into perfectly formatted PDFs and automatically distribute them.

The Solution

I built DocuGen Pro, a comprehensive SaaS platform that automates the entire document lifecycle via a dynamic template system and Artificial Intelligence.

Watch the Platform Demonstration:

Read the full Technical Report (PDF)

The application was designed with a microservices-ready architecture, heavily decoupling the frontend from the backend. Here is a breakdown of the core technical implementation:

(Note: System architecture mapping the core entities and controllers)

1. AI-Powered Template Generation

To eliminate the friction of building templates from scratch, I integrated the Groq API (running the Llama 3.3 70B model) via asynchronous WebClient.

• Administrators simply provide a text description of the document they need.
• Through specific prompt engineering, the AI generates a strictly structured JSON file.
• This JSON defines the required form fields (Text, Number, Date, Signature) and the underlying HTML structure.

2. Dynamic Frontend (Angular 17)

The frontend acts as a Single Page Application (SPA) built with Angular 17 and styled via Tailwind CSS and Angular Material.

(Note: Sequence diagram illustrating the dynamic JSON template hydration)

• Challenge: I needed to render form inputs dynamically based on an unknown, AI-generated JSON structure.
• Fix: I utilized Angular’s Reactive Forms to iterate through the JSON payload, instantiating new FormControl objects on the fly with conditional validators (like @Required) depending on the field type.

3. Robust PDF & Email Pipeline

The backend, powered by Spring Boot 3, manages a sophisticated rendering pipeline:

• Data submitted by the user hydrates the template via Thymeleaf, replacing {{variables}} with real inputs.
• Challenge: Unclosed HTML tags would instantly break the PDF parser.
• Fix: I implemented Jsoup as an intermediary step to aggressively parse and clean the raw HTML into strictly compliant XML/XHTML.
• The sanitized output is passed to OpenPDF / Flying Saucer for rapid rendering (< 1 second).
• Finally, JavaMailSender automatically attaches the generated PDF and emails it to the recipient.

4. Secure Stateless Architecture

To ensure high scalability and security, the system relies on a stateless architecture.

• Authentication is handled via JWT tokens implemented through Spring Security Filters.
• Role-Based Access Control (RBAC) strictly separates standard USER endpoints from ADMIN template management using @PreAuthorize annotations.
• Data is persisted securely in a PostgreSQL database mapped via JPA/Hibernate.

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The Results

DocuGen Pro successfully transformed a tedious manual chore into an automated, one-click workflow.

By leveraging Llama 3 for structure generation and a highly optimized Thymeleaf-to-PDF pipeline, the platform achieved a 80% reduction in document creation time for end-users. The system remains fully extensible, capable of generating everything from simple NDAs to complex, multi-page freelance contracts without requiring a single line of new code.