Pneumatic is an open-source SaaS workflow management system built with a Django backend and React/TypeScript frontend. The platform enables users to create workflow templates, execute workflows, manage tasks, collaborate with teams, and track progress through a comprehensive UI. It features multi-tenancy, payment processing (Stripe integration), notification systems, file attachments, reporting, and various third-party integrations. The architecture follows a microservices-like separation using Docker Compose, with distinct services for backend, frontend, database (PostgreSQL), caching (Redis), messaging (RabbitMQ), and file storage. The codebase demonstrates solid engineering practices with clear separation of concerns, though it shows some technical debt from using Django 2.2 and accumulated migration complexity.