Blanked a little on how to structure this without sounding like I was reading from a textbook.
Start with a clear, concise definition of an API as a contract that allows different software components to communicate. Then explain the request-response cycle, including how a client sends a request to an endpoint and receives a response, and briefly mention different API styles (e.g., REST, GraphQL, RPC). Finally, connect it to real-world examples or trade-offs to show practical understanding.
Pro tip: Emphasize that APIs are about abstraction and decoupling: they hide implementation details and enable independent evolution of systems. Mentioning versioning, rate limiting, or idempotency can demonstrate production-level awareness.
State that an API (Application Programming Interface) is a set of rules and protocols that allows different software applications to communicate with each other. It defines the methods and data formats that developers can use to interact with a service.
Describe how a client (e.g., a web browser or mobile app) sends a request to an API endpoint, typically over HTTP. The request includes a method (GET, POST, etc.), headers, and sometimes a body. The server processes the request and returns a response with a status code and data (often JSON).
Mention common API architectural styles like REST, GraphQL, and gRPC, and note that they differ in how they structure requests and responses. REST is resource-oriented, GraphQL allows clients to request specific data, and gRPC uses protocol buffers for high-performance communication.
Bring up important aspects such as authentication (API keys, OAuth), rate limiting, versioning, and error handling. These ensure security, reliability, and backward compatibility.
Give a concrete example, such as how Meta's Graph API allows developers to access social graph data, or discuss trade-offs between REST and GraphQL (e.g., over-fetching vs. flexibility). This shows practical insight.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.