Built an intelligent document extraction engine that automatically parses invoices using GPT-4 Vision. The system extracts 15+ field types (vendor info, line items, totals, dates) with 93.5% accuracy and includes confidence scoring for each field. Key features: - Multi-modal LLM processing for PDF, images, and scanned documents - Cross-validation logic that catches extraction errors by comparing line totals vs subtotals - Async batch processing for high-volume workflows - Pydantic schemas for type-safe, structured output Tech: Python, GPT-4 Vision, LangChain, Pydantic, FastAPI