Decagon Software Engineer Interview Experience — A "System Design" Screen That Was Really Data Modeling

When they scheduled the interview they said it would be one System Design round, but the interviewer said right at the start that scalability was not a consideration and the focus was more on designing the data model. I think it felt a bit like an OOD design round.

Design a rule management system that allows customers to configure behavioral rules for AI agents, such as “Be polite,” “Keep responses under three sentences,” or “Avoid political discussions.”

Customers can create, update, and delete rules, save drafts, publish configurations, and roll back to previous deployments. An external Agent Renderer (black boxed) retrieves the active rules to execute. Focus on data models, APIs, and data flow.