File Uploads & Streams

Introduction

In this lesson, we dive into handling file uploads and streams — an essential skill for building CMS platforms, portfolios, or any project involving images, videos, or documents.

What you’ll learn

• Accepting file uploads via form-data

• Using multer or busboy for stream-based parsing

• Validating files by type, size, and security constraints

• Saving files to disk or streaming them to cloud storage (e.g., S3)

• Serving uploaded files as public assets or private resources

Why this matters

Efficient media handling improves performance and user experience. You’ll understand how to support large files without blocking the event loop, and how to design file APIs that are secure and flexible.