Justin wants to take Rails off the rails...

config.ru

require "rack"

class Application
  def call(env)
    status = 200
    headers = { "Content-Type" => "text/html" }
    body = ["<h1>WHY?</h1>"]

    [status, headers, body]
  end
end

class First
  def initialize(app)
    @app = app
  end

  def call(env)
    body1 = Second.new(@app).call(env).last
    body2 = AlsoSecond.new(@app).call(env).last

    status, headers, body = @app.call(env)
    [status, headers, body2 + body1 + body]
  end
end

class Second
  def initialize(app)
    @app = app
  end

  def call(env)
    status, headers, body = @app.call(env)
    [status, headers, ["<h2>Why Justin</h2>"]]
  end
end

class AlsoSecond
  def initialize(app)
    @app = app
  end

  def call(env)
    status, headers, body = @app.call(env)
    [status, headers, ["<h3>WHY?</h3>"]]
  end
end

use First
run Application.new