gem "stackprof", ">= 0.2.26", require: false

require "stackprof"

def profile!
  profile =
    StackProf.run(ignore_gc: true, interval: 1000, mode: :wall, raw: true) do
      @value = # slow code
    end

  output_file = Rails.root.join("log/stackprof.json")  
  File.write(output_file, JSON.generate(profile))

  @value # return the original  
end

profile!

scp PROD:/path/to/log/stackprof.json ~/Desktop/profile.json