ARCHITECTURE

System Architecture Overview

Module	Description	Technologies & Integrations
Frontend	User interface for the auction platform (bidding, auction browsing, dashboards, real-time updates)	Angular, RxJS, HTTP REST, WebSocket / SSE for real-time updates
BFF (Backend For Frontend)	Intermediate layer between frontend and backend services; aggregates and simplifies API responses for UI	Nest.js, REST API, JWT authentication handling, API composition, WebSocket gateway
Business Rules Engine (Binding Rules Module)	Handles dynamic business rules (bid validation, auction constraints, pricing rules)	Drools, Spring Cloud Function, Spring Boot, optional Redis cache, rule execution engine
Workflow Orchestrator (Core Module)	Main business process orchestration module (auction lifecycle, bidding flow, approvals, process automation)	Spring Boot, Camunda, BPMN, PostgreSQL, REST connectors
Event Archive (Logs & History)	Event storage and history system (audit logs, event sourcing, analytics, replay capability)	Spring WebFlux, Kafka, Cassandra, reactive streams, event-driven architecture, Camel