Ensure you’re handling file sizes, storage, and security configurations correctly in your file upload setup.

Issues with file uploads in Node.js can be caused by several factors, including file size limits, incorrect storage paths, and security configurations, all of which can affect successful uploads. Begin by verifying the middleware you’re using, such as multer or formidable, and ensure that file size limits are configured to handle the desired upload sizes—misconfigured limits can lead to files being dropped or requests failing silently. Set your storage paths correctly, particularly if using cloud storage services like AWS S3, by ensuring that the app has correct permissions and that paths are accurately defined to avoid storage failures. Pay close attention to security settings; for example, setting file restrictions by type and validating filenames can prevent malicious files from being uploaded and executed. Additionally, if you are handling files in temporary storage before processing, implement cleanup routines to prevent accumulated files from consuming storage, which can slow down or break the app over time. Testing the upload functionality in a controlled environment helps verify that all configurations are set correctly for successful and secure file uploads.