Delegate all methods to the decorated class and benchmark each call.

benchmarker.rb

require 'benchmark'

class Benchmarker < SimpleDelegator

  def method_missing(method, *args, &block)
    __log__ "Running #{ method }(#{ args.inspect.gsub(/^\[|\]$/, '') })"

    result = nil
    __benchmark__ { result = super }

    result
  end

  def __benchmark__(&blk)
    __log__ Benchmark::CAPTION
    __log__ Benchmark.measure(&blk)
  end

  def __log__(*messages)
    puts *messages
  end

  # I didn't want to benchmark every call to inspect that irb calls.
  # But you could undef this if you want to benchmark inspect.
  def inspect
    "#<Benchmarker for:#{ __getobj__.inspect }>"
  end
end

Example usage:

startup = Startup.new
startup.bootstrap
startup.start_burning_out
startup.look_for_funding

Hmm, which of those methods is taking the longest...

startup = Benchmarker.new(Startup.new)
startup.bootstrap
startup.start_burning_out
startup.look_for_funding