Sucker Punch is a single-process Ruby asynchronous processing library. This
reduces costs of hosting on a service like Heroku along with the memory
footprint of having to maintain additional jobs if hosting on a dedicated
server. All queues can run within a single application (eg. Rails, Sinatra,
etc.) process.

Sucker Punch is perfect for asynchronous processes like emailing, data
crunching, or social platform manipulation. No reason to hold up a user when you
can do these things in the background within the same process as your web
application.

Sucker Punch is built on top of concurrent-ruby. Each job is setup as a pool,
which equates to its own queue with individual workers working against the jobs.
Unlike most other background processing libraries, Sucker Punch's jobs are
stored in memory. The benefit to this is there is no additional infrastructure
requirement (ie. database, redis, etc.). However, if the web processes are
restarted with jobs remaining in the queue, they will be lost. For this reason,
Sucker Punch is generally recommended for jobs that are fast and non-mission
critical (ie. logs, emails, etc.).

WWW: https://github.com/brandonhilkert/sucker_punch