Getting s3 objects with Rails
There are two issues you should watch out for:


This will block the current thread while it's running. For a large file, this could be a substantial amount of time. You should consider moving this code out to a Sidekiq (or similar) worker, so that you aren't blocking threads in your web app.
When you rescue exceptions, you just puts them, which you're likely to ignore in production. You should be logging that exception to a place that you can get ahold of it later. I would personally just not rescue it and use BugSnag or similar in my application to ensure that errors are collected and kept for resolution.