Gemini Enterprise enables developers to build custom AI agents for employee onboarding using the Agent Development Kit (ADK), Agent Engine, and Application Integration. The architecture combines conversational AI with enterprise systems (ITSM, ERP, CRM) through a three-layer approach: a natural language interface, a low-code automation layer, and backend system integration. A practical example demonstrates how an HR employee can request a laptop through simple conversation, while the agent handles intent understanding, data transformation, authentication, and ITSM ticket creation behind the scenes. The solution uses Application Integration workflows as API endpoints configured as tools in ADK code, then published to the Gemini Enterprise agent gallery for employee access.