What is metric?

An API, or Application Programming Interface, is a set of rules and tools that lets different software programs talk to each other. Think of it as a menu in a restaurant: the menu lists what dishes (functions) you can order, and the kitchen (the program) prepares them for you without you needing to know the cooking details.

Let's break it down

  • Endpoint: The specific URL where a request is sent.
  • Request: Your program asks for something (data, action) using a method like GET or POST.
  • Response: The server sends back the result, often in JSON or XML format.
  • Authentication: A way to prove who you are, such as API keys or tokens.
  • Rate limiting: Rules that limit how many requests you can make in a given time.

Why does it matter?

APIs let developers build powerful apps quickly by reusing existing services instead of writing everything from scratch. They enable integration between apps, automate tasks, and power the connected experiences we use every day-like logging in with Google, checking the weather in a travel app, or posting to social media from another platform.

Where is it used?

  • Mobile apps (e.g., fetching user data from a server)
  • Websites (e.g., loading product listings from a backend)
  • Cloud services (e.g., AWS, Azure APIs for managing resources)
  • IoT devices (e.g., sending sensor data to a central hub)
  • Third‑party integrations (e.g., payment gateways, mapping services)

Good things about it

  • Speed: Build features faster by leveraging existing services.
  • Scalability: Separate components can grow independently.
  • Flexibility: Different languages and platforms can interact.
  • Maintainability: Changes in one service don’t break others if the API contract stays the same.
  • Ecosystem: Large communities share public APIs, fostering innovation.

Not-so-good things

  • Complexity: Managing many endpoints, versions, and authentication can become tricky.
  • Reliance on external services: If an API goes down, your app may break.
  • Security risks: Poorly designed APIs can expose data or be vulnerable to attacks.
  • Rate limits: Hitting usage caps can interrupt functionality.
  • Versioning headaches: Updating an API without breaking existing clients requires careful planning.