Bare bone, no-library, no-error handling, just the very core idea behind FP objects in Ruby

bare-bone-fp-ruby-objects.rb

class CreateStuff
  def initialize(stuff_repo)
    @stuff_repo = stuff_repo
  end
  
  def call(params)
    @stuff_repo.create(params)
  end
end

class BuildEverything
  def initialize(create_stuff)
    @create_stuff = create_stuff
  end
  
  def call(params)
    1000.times { |i| @create_stuff.call(params.merge(num: i, foo: "foo-#{i}")) }
  end
end

create_stuff = CreateStuff.new(stuff_repo) # let's assume we got stuff_repo already

build_everything = BuildEverything.new(create_stuff)

# so now I have access to creating stuff however I want
create_stuff.call(num: 312, foo: "bar")

# and some higher-level concept built on top
build_everything.call(baz: "xyz")

# this means we have stand-alone, re-usable objects, that we can pass around, compose freely together and so on