DocAnalyzer

DocAnalyzer maintains coherent context across entire multi-page documents (PDFs, research papers) during conversational interactions by implementing a sliding-window or hierarchical chunking strategy that preserves semantic relationships between sections. The system likely uses vector embeddings to retrieve relevant passages while maintaining document structure awareness, enabling follow-up questions that reference earlier sections without losing narrative continuity across 50+ page documents.

DocAnalyzer implements a no-authentication, no-signup flow where users can immediately upload a document and begin conversing without account creation, email verification, or payment setup. The system likely uses temporary session-based storage (Redis or in-memory cache) with automatic cleanup, and pre-loads document embeddings asynchronously while the user types their first question, eliminating perceived latency.

DocAnalyzer converts user questions into semantic queries using embeddings (likely OpenAI's text-embedding-3-small or open-source alternatives like all-MiniLM-L6-v2) to retrieve relevant document passages, then passes retrieved context to an LLM for answer generation. The system implements a two-stage retrieval pattern: semantic similarity search for initial passage ranking, followed by LLM-based re-ranking or direct answer synthesis, enabling questions phrased in natural language without requiring keyword matching or boolean operators.

DocAnalyzer accepts PDF uploads and extracts text content using a PDF parsing library (likely PyPDF2, pdfplumber, or PDFMiner), with automatic fallback to optical character recognition (OCR) for scanned documents or image-based PDFs. The system likely detects whether a PDF contains selectable text or is image-only, routing scanned documents through an OCR engine (Tesseract, EasyOCR, or cloud-based service) before embedding and indexing.

DocAnalyzer maintains implicit conversation state where follow-up questions automatically reference the uploaded document without explicit re-specification. The system stores the document embedding vector and retrieval index in the session, allowing subsequent questions to query the same document context without re-uploading or re-indexing. Multi-turn conversations are managed through a conversation history buffer that tracks previous questions and answers, enabling anaphora resolution ('it', 'this', 'that') and topic continuity.

DocAnalyzer generates answers by passing retrieved document passages and user questions to a language model (likely OpenAI GPT-3.5-turbo or GPT-4, with possible fallback to open-source models), implementing streaming response delivery where tokens are sent to the browser as they are generated rather than waiting for full completion. The system likely uses server-sent events (SSE) or WebSocket connections to stream responses in real-time, reducing perceived latency and enabling users to start reading answers before generation completes.

DocAnalyzer chunks uploaded documents into semantic units (likely 256-512 token windows with overlap), generates embeddings for each chunk using a pre-trained embedding model, and stores embeddings in a vector database for similarity-based retrieval. The indexing process happens asynchronously after document upload, allowing users to start asking questions while embeddings are still being generated. The system likely uses approximate nearest neighbor (ANN) search (FAISS, Annoy, or database-native vector search) to retrieve top-K relevant passages in sub-100ms latency.

DocAnalyzer stores uploaded documents and their embeddings in temporary, session-scoped storage (likely Redis with TTL, in-memory cache, or ephemeral cloud storage) that automatically expires after a fixed timeout (24-48 hours) or browser session end. The system does not persist documents to permanent storage or user accounts, eliminating data retention liability and reducing infrastructure costs. Cleanup is automatic and non-configurable — users cannot extend session duration or export documents for later access.