Your application lets users upload profile pictures.
At first, you save them inside the project directory.
It works.
Then you deploy again.
Some files disappear.
Why?
Because application code and user-generated data have completely different lifecycles.
Code Changes. User Data Shouldn't
Your Git repository changes every time you release a new version.
User uploads shouldn't disappear every time you deploy a new version.
That's why storing production uploads inside the application source directory can become a problem.
Think About the Difference Application code → Git → Deployments
User uploads → Persistent storage → Long-term data
They need different storage strategies.
What Happens During a New Deployment?
Depending on the infrastructure, the new application container may be created from scratch.
If your uploads existed only inside the previous container, the new container may not have them.
What Should You Store?
Common examples of persistent data include:
User uploads Generated reports Media Documents Important application files
The correct storage system depends on your application architecture.
Don't Confuse Storage With Backups
Persistent storage keeps your files available.
A backup gives you a recovery option.
Important data may need both.
Design This Before Launch
If your application will accept user uploads, decide where those files live before real users start uploading them.
Changing storage architecture after thousands of files exist is much more painful.
Application containers are disposable. User data shouldn't be.