Handling Large Files
A user tries to upload a 2 GB video file. After 45 minutes at 80% progress, their connection drops. They have to start over from scratch.
Meanwhile, your server is struggling. Memory usage spikes as it tries to buffer the entire file. The request times out. Other users experience slowdowns because one large upload is hogging resources.
This is the reality of naive file handling. And it gets worse at scale.
Every major platform, from Dropbox to YouTube to Google Drive, has had to solve this problem. The good news is that the solutions are well-established patterns that you can apply to any system that handles files larger than a few megabytes.
In this chapter, we will walk through these patterns step by step. We will start with understanding why simple approaches break down, then build up to production-grade solutions for both uploads and downloads.