uploads

When clients upload files directly to S3, your API avoids handling large payloads and you get better scalability. I generate a presigned PUT URL with a short expiry and a constrained object key prefix so users can’t overwrite arbitrary objects. The cr

Multipart uploads are a common DOS vector if you let them allocate unbounded memory. I cap the request with http.MaxBytesReader, keep ParseMultipartForm bounded, and copy the file stream into a temp file using io.Copy. This avoids holding the whole fi

For image uploads, I like immediate previews. With Active Storage, you can render the preview server-side once the blob is attached, and use Turbo Streams to update the preview area. The form submits to an endpoint that attaches the blob and returns a

Direct uploads are great because they keep file traffic away from your Rails dynos, but the default UX is opaque. I attach a Stimulus controller that listens for Active Storage’s direct-upload:* events and updates a progress bar. This keeps the markup

Clients can lie about Content-Type, so for uploads I prefer sniffing the first bytes with http.DetectContentType. The safe flow is: open the multipart file, read a small prefix, detect type, then rewind (or re-open) before writing to disk or object st

Large file uploads don’t belong on app servers. My default is: the server issues a short-lived pre-signed URL, the browser uploads directly to S3, then the server stores the object key. That keeps latency low and costs predictable. Before signing, I v

File uploads require careful validation for security. I validate file size using a custom validator and check content type. Using FileField or ImageField, Django handles storage automatically. I configure MEDIA_ROOT and MEDIA_URL for development. For

Multipart uploads can blow up memory if you parse them naively. With busboy, I stream file data as it arrives and enforce size limits and content-type checks early. I avoid writing to disk unless I need it; for many flows I stream directly to object s