Architecture & DFD
Advanced Data Flow Diagram -- uploads, storage, underwriting, analytics, AI
System Architecture -- Layer View
Presentation Layer
Web Application
Next.js / React
SPA with SSR for SEO and performance
Dashboard
Recharts / D3
Real-time analytics and KPI visualization
AI Chat Interface
WebSocket / REST
Multi-provider AI conversation UI
API Layer
REST API Gateway
Node.js / Express
Rate-limited, authenticated endpoints
Excel Conversion API
Data Pipeline
Parse XLSX/CSV to structured JSON
AI Orchestration
Multi-Provider Router
OpenAI, Anthropic, Google routing
Data & Storage Layer
PostgreSQL
Primary Database
Deals, users, underwriting, permissions
Cloudflare R2
Object Storage
Documents, Excel files, media assets
Vector Store
Embeddings / RAG
Document embeddings for AI search
Security Layer
Auth & RBAC
JWT + Row-Level
Role-based access with row-level policies
Encryption
AES-256-GCM
At-rest and in-transit encryption
Audit Log
Event Tracking
Full audit trail for compliance
Data Flow Diagrams
File received via multipart upload API
Classification engine labels as public/private/internal
File encrypted with AES-256-GCM
Stored in Cloudflare R2 under /deals/[deal_id]/
Parser extracts structured data (income, expenses, debt)
Structured data written to PostgreSQL
Document embeddings generated for AI vector store
API receives deal parameters (price, NOI, loan terms)
Rate-cap calculation: max(index + spread, strike + spread)
DSCR computed: NOI / annual debt service
Sensitivity matrix generated across rate/NOI scenarios
Exit analysis: projected NOI, exit valuation, IRR
Flag engine checks thresholds (DSCR < 1.2x, LTV > 75%)
Results cached and returned with confidence intervals
User query received with context (deal IDs, permissions)
Permission filter applied (only permitted data accessible)
Relevant documents retrieved from vector store (RAG)
Query + context sent to selected AI provider
Response parsed with explainability metadata
Source attribution linked to original documents
Usage tracked against per-user token cap