What is Serverless?

Serverless is a cloud computing model where you deploy code without managing servers. Instead of provisioning, scaling, and maintaining machines, you write short-lived functions that run on-demand.

What It Is — Technically:

In serverless, the cloud provider (like AWS, Google Cloud, or Vercel) handles the infrastructure. When an event triggers your code — an HTTP request, a cron job, a queue message — your function is executed in a managed environment. You only pay for the time your code runs, measured in milliseconds.

Serverless functions are typically:

• Stateless (they don’t persist data between runs)
• Ephemeral (they spin up and shut down automatically)
• Triggered by events (like API calls, file uploads, DB changes)

How It Works:

• You write your function (usually in Node.js, Python, Go, etc.)
• Deploy it to a serverless platform
• The provider handles scaling, execution, and teardown
• You’re billed based on usage, not uptime

Under the hood, these platforms often use lightweight containers or WebAssembly modules running inside secure, isolated environments — sometimes even Virtual Machines for compatibility or isolation.

Why You’d Use It:

• Focus on business logic, not infrastructure
• Scale automatically with demand
• No idle cost — you don’t pay when nothing’s happening
• Quick to deploy for prototypes and production
• Integrates well with APIs, events, and background tasks

When Not to Use Serverless:

• When you need persistent state or long-running processes
• If cold-start latency is unacceptable (e.g., real-time trading)
• If vendor lock-in or observability limitations are a concern
• For heavy-duty compute tasks better handled in long-lived VMs or containers

Real-World Example:

A contact form on your website uses a serverless function to send emails via an API. It only runs when a user submits the form — saving you infrastructure cost and scaling to handle spikes without effort.