You can use Sidekiq with Upstash Redis. Sidekiq is a Ruby based queue library with a Redis-based queue storage so you can use with Upstash Redis.

Example Application

bundle init 
bundle add sidekiq
require "sidekiq"
require "sidekiq/api"
 
connection_url = ENV['UPSTASH_REDIS_LINK']
 
Sidekiq.configure_client do |config|
    config.redis = {url: connection_url}
end
 
Sidekiq.configure_server do |config|
    config.redis = {url: connection_url}
end
 
class EmailService
    include Sidekiq::Worker
    def perform(id, type)
        # Logic goes here. Let's assume sending email by printing to console.
        puts "Emailed to: " +  id + ": " + "'Congrats on " + type + " plan.'"
    end
end
 
def updateEmail(id, newType)
    jobFound = false
 
    a = Sidekiq::ScheduledSet.new
    a.each do |job|
        if job.args[0] == id
            job.delete
            jobFound = true
        end
    end
 
    if jobFound
        EmailService.perform_async(id, ("starting using our service and upgrading it to " + newType))
    else
        EmailService.perform_async(id, ("upgrading to " + newType))
    end
end
 
def sendEmail(id, type)
    case type
    when "free"
        # if free, delay for 10 seconds.
        EmailService.perform_in("10", id, "free")
    when "paid"
        # if paid, delay for 5 seconds.
        EmailService.perform_in("5", id, "paid")
    when "enterprise"
        # if enterprise, immediately queue.
        EmailService.perform_async(id, "enterprise")
    when "enterprise10k"
        EmailService.perform_async(id, "enterprise10k")
    else
        puts "Only plans are: `free`, `paid` and `enterprise`"
    end
end
 
def clearSchedules()
    Sidekiq::ScheduledSet.new.clear
    Sidekiq::Queue.new.clear
end

Billing Optimization

Sidekiq accesses Redis regularly, even when there is no queue activity. This can incur extra costs because Upstash charges per request. With feedbacks of Sidekiq users, we have revised our billing algorithm. Now, Upstash detects Sidekiq usage and charges only for script calls instead of each Redis operation for Sidekiq operations. This will avoid increased command count and high costs due to Sidekiq library. We have decided to charge only for script calls instead of all requests. This special pricing is for Sidekiq users. If you use Sidekiq with Upstash Redis, you will only be charged for script calls, not regular requests. This will significantly reduce your costs.

Once your billing is in optimized mode, you will see a leaf icon in the console like below:

This mechanism is enabled for all tiers except free databases.