As I take great pains to discuss in both https://sustainable-rails.com and https://sidekiqrails.com, to use background jobs you MUST understand how the job backend works. Active Job is just an API, it's not an abstraction. You MUST understand the fine details of how Solid Queue (or Sidekiq or Resque) is implemented. Otherwise, you cannot operate it for true production workloads.
Resque and Sidekiq are pretty simple and knowledge of their behavior is widespread in the industry.