DocGardAI
Engineering

Building a Forensic AI Engine: Handling High-Fidelity Image Processing in Python

Jeff Enterprises Engineering
February 2026

Building a robust AI tool requires more than just a clever algorithm; it requires an architecture capable of handling heavy computational loads without sacrificing user experience. When developing DocGard AI, our engineering team had to architect a system that could process high-fidelity PDFs and JPEGs in real-time.

The Decoupled Architecture

We opted for a strictly decoupled architecture. The frontend is built with React and Next.js, hosted globally on Vercel's Edge Network for sub-second load times. However, Next.js is not optimized for heavy mathematical image processing. Therefore, the core Error Level Analysis (ELA) logic was abstracted into an independent Python backend.

Python, FastAPI, and Pillow

The backend API is powered by FastAPI, chosen for its asynchronous capabilities and speed. When a user uploads a document, the API utilizes the PyMuPDF library to securely extract raw image data from PDFs without altering the underlying cryptographic signatures. The Pillow library then handles the pixel-by-pixel compression rate subtraction necessary for the ELA heatmap generation.

Stateless Cloud Deployment

To ensure scalability, the Python engine operates as a stateless service deployed on Render. Because the application does not store files locally or rely on a persistent database, it can instantly scale up during traffic spikes and safely wipe temporary server memory (RAM) after every scan, guaranteeing strict data privacy for our users.