Uploading video to S3 via sidekiq / Carrierwave on Heroku rails app

I have a Rails 7 app running on Heroku. The app is simple, in theory: Users sign up, and can upload video files as part of a survey.

I'm using Carrierwave for the upload process, but ran into memory and timeout issues using Heroku. I've tried to implement the carrierwave-backgrounder gem alongside sidekiq and redis.

I've pushed to a staging app on Heroku and the timeouts on form submit seem to be resolved, but the files aren't being uploaded to the S3 bucket. I've set the S3 credentials in the staging app's config vars the same as on the production app.

Inspecting the Video record in the rails console shows filenames in the relevant table columns, but no files are showing in the S3 bucket.

Video.rb:

class Video < ApplicationRecord  mount_uploaders :video_files, VideoUploader  store_in_background :video_filesend

carrierwave.rb

CarrierWave.configure do |config|  config.fog_credentials = {    provider:              'AWS',                        # required    aws_access_key_id:     ENV.fetch('AWS_ACCESS_KEY_ID'),                        # required unless using use_iam_profile    aws_secret_access_key: ENV.fetch('AWS_SECRET_ACCESS_KEY'),                        # required unless using use_iam_profile    use_iam_profile:       true,                         # optional, defaults to false    region:                ENV.fetch('AWS_REGION')                  # optional, defaults to 'us-east-1'  }  config.fog_directory  = ENV.fetch('S3_BUCKET_NAME')                                    # required  config.fog_public     = false                                                 # optional, defaults to true  config.fog_attributes = { cache_control: "public, max-age=#{365.days.to_i}" } # optional, defaults to {}  # For an application which utilizes multiple servers but does not need caches persisted across requests,  # uncomment the line :file instead of the default :storage.  Otherwise, it will use AWS as the temp cache store.  # config.cache_storage = :fileend

VideoUploader.rb

class VideoUploader < CarrierWave::Uploader::Base  include ::CarrierWave::Backgrounder::Delay  cache_storage CarrierWave::Storage::File  def cache_dir"uploads_cache/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"  end  storage :fog  def store_dir"uploads/#{model.class.to_s.underscore}/#{mounted_as}/#{model.id}"  end  def extension_allowlist    %w(mp4 mov avi)  endend

initializers/carrierwave_backgrounder.rb

CarrierWave::Backgrounder.configure do |c|  c.backend :sidekiq, queue: :carrierwaveend

initializers/sidekiq.rb

Sidekiq.configure_server do |config|  config.redis = {    url: ENV["REDIS_URL"],    ssl_params: { verify_mode: OpenSSL::SSL::VERIFY_NONE }  }endSidekiq.configure_client do |config|  config.redis = {      url: ENV["REDIS_URL"],      ssl_params: { verify_mode: OpenSSL::SSL::VERIFY_NONE }  }end

sidekiq.yml

:queues:  - [carrierwave, 1]  - default

redis.rb

$redis = Redis.new(url: ENV["REDIS_URL"], ssl_params: { verify_mode: OpenSSL::SSL::VERIFY_NONE })

Procfile

worker: bundle exec sidekiq -c 2