MCP Enterprise Architecture: Gateways, Transport, and Tool Contracts

Model Context Protocol interviews increasingly appear in enterprise agent roles. Interviewers test whether you understand MCP as a contract layer between clients and tool servers—not just another plugin format. Discuss transport options, capability discovery, and how gateways centralize auth while distributing tool implementations.

Enterprise MCP architecture usually adds a gateway for authentication, rate limiting, audit logging, and schema validation. Candidates explain how clients discover allowed tools per tenant, how resource URIs map to internal APIs, and how you prevent agents from chaining tools into unintended side effects.

Tool and resource design mirrors good API design: narrow interfaces, explicit error codes, pagination for large results, and versioning. Interviewers ask how you handle breaking schema changes across dozens of MCP servers without bricking production agents.

Observability spans client sessions, server handlers, and downstream API latency. Describe distributed tracing from agent intent through MCP calls to backend systems. Without correlation IDs, cross-team incidents become blame ping-pong.

Compare MCP to REST and internal SDK approaches honestly. MCP wins on ecosystem interoperability and dynamic discovery; it loses on maturity and operational patterns in some orgs. Strong candidates articulate migration paths and when not to adopt MCP for simple, stable integrations.