diff --git a/Gemfile b/Gemfile
index c4c9c13..7edc325 100644
--- a/Gemfile
+++ b/Gemfile
@@ -19,6 +19,7 @@ end
 group :tools do
   gem 'rubocop', '~> 0.31'
 
+  gem 'faker'
   gem 'guard'
   gem 'guard-rspec'
   gem 'guard-rubocop'
diff --git a/README.md b/README.md
index 3d2af0b..1a90a6d 100644
--- a/README.md
+++ b/README.md
@@ -21,6 +21,16 @@ Resources:
 - [Guides](http://rom-rb.org/guides/basics/mappers/)
 - [Importing Data with ROM and Transproc](http://solnic.eu/2015/07/15/importing-data-with-rom-and-transproc.html)
 
+Contributing
+
+[Fork it](https://github.com/rom-rb/rom-mapper/fork)
+Create your feature branch (`git checkout -b my-new-feature`)
+Run the benchmark suite (`bin/benchmarks`)
+Commit your changes (`git commit -am 'Add some feature'`)
+Run the benchmark suite again for comparison (`bin/benchmarks`)
+Push to the branch (`git push origin my-new-feature`)
+Create a new Pull Request
+
 ## License
 
-See `LICENSE` file.
+See [LICENSE](blob/master/LICENSE) file.
diff --git a/benchmarks/model_instantiation b/benchmarks/model_instantiation
new file mode 100755
index 0000000..d4fdeb0
--- /dev/null
+++ b/benchmarks/model_instantiation
@@ -0,0 +1,23 @@
+#!/usr/bin/env ruby
+# encoding: utf-8
+
+require_relative 'utils/setup.rb'
+
+user_model = Class.new(OpenStruct)
+
+mapper = build_mapper do
+  attribute :name
+  attribute :email
+  model user_model
+end
+
+tuples = create_tuple_collection(100) do
+  {
+    name: Faker::Name.name,
+    email: Faker::Internet.email
+  }
+end
+
+run('model_instantiation') do |x|
+  x.report { mapper.call(tuples) }
+end
diff --git a/benchmarks/noop b/benchmarks/noop
new file mode 100755
index 0000000..7e28600
--- /dev/null
+++ b/benchmarks/noop
@@ -0,0 +1,20 @@
+#!/usr/bin/env ruby
+# encoding: utf-8
+
+require_relative 'utils/setup.rb'
+
+mapper = build_mapper do
+  attribute :name
+  attribute :email
+end
+
+tuples = create_tuple_collection(100) do
+  {
+    name: Faker::Name.name,
+    email: Faker::Internet.email
+  }
+end
+
+run('noop') do |x|
+  x.report { mapper.call(tuples) }
+end
diff --git a/benchmarks/reject_keys b/benchmarks/reject_keys
new file mode 100755
index 0000000..a1362b5
--- /dev/null
+++ b/benchmarks/reject_keys
@@ -0,0 +1,22 @@
+#!/usr/bin/env ruby
+# encoding: utf-8
+
+require_relative 'utils/setup.rb'
+
+mapper = build_mapper do
+  reject_keys true
+  attribute :name
+  attribute :email
+end
+
+tuples = create_tuple_collection(100) do
+  {
+    name: Faker::Name.name,
+    email: Faker::Internet.email,
+    Faker::Lorem.word => Faker::Lorem.word
+  }
+end
+
+run('reject_keys') do |x|
+  x.report { mapper.call(tuples) }
+end
diff --git a/benchmarks/rename_keys b/benchmarks/rename_keys
new file mode 100755
index 0000000..1cc478b
--- /dev/null
+++ b/benchmarks/rename_keys
@@ -0,0 +1,20 @@
+#!/usr/bin/env ruby
+# encoding: utf-8
+
+require_relative 'utils/setup.rb'
+
+mapper = build_mapper do
+  attribute :name, from: 'name'
+  attribute :email, from: 'email'
+end
+
+tuples = create_tuple_collection(100) do
+  {
+    'name' => Faker::Name.name,
+    'email' => Faker::Internet.email
+  }
+end
+
+run('rename_keys') do |x|
+  x.report { mapper.call(tuples) }
+end
diff --git a/benchmarks/results/model_instantiation b/benchmarks/results/model_instantiation
new file mode 100644
index 0000000..030e415
--- /dev/null
+++ b/benchmarks/results/model_instantiation
@@ -0,0 +1,10 @@
+=> benchmark: model_instantiation
+=> host: andy-HP-ENVY-TS-15-Notebook-PC
+=> revision: b7df14f0aacb67d1e006bf1795e0ca45481bc925
+=> repo_state: clean
+
+Calculating -------------------------------------
+                       167.000  i/100ms
+-------------------------------------------------
+                          1.612k (±10.0%) i/s -      8.016k
+********************************************************************************
diff --git a/benchmarks/results/noop b/benchmarks/results/noop
new file mode 100644
index 0000000..058ff07
--- /dev/null
+++ b/benchmarks/results/noop
@@ -0,0 +1,10 @@
+=> benchmark: noop
+=> host: andy-HP-ENVY-TS-15-Notebook-PC
+=> revision: b7df14f0aacb67d1e006bf1795e0ca45481bc925
+=> repo_state: clean
+
+Calculating -------------------------------------
+                        90.342k i/100ms
+-------------------------------------------------
+                          1.497M (± 4.5%) i/s -      7.498M
+********************************************************************************
diff --git a/benchmarks/results/reject_keys b/benchmarks/results/reject_keys
new file mode 100644
index 0000000..d93113f
--- /dev/null
+++ b/benchmarks/results/reject_keys
@@ -0,0 +1,10 @@
+=> benchmark: reject_keys
+=> host: andy-HP-ENVY-TS-15-Notebook-PC
+=> revision: b7df14f0aacb67d1e006bf1795e0ca45481bc925
+=> repo_state: clean
+
+Calculating -------------------------------------
+                       492.000  i/100ms
+-------------------------------------------------
+                          4.925k (± 6.8%) i/s -     24.600k
+********************************************************************************
diff --git a/benchmarks/results/rename_keys b/benchmarks/results/rename_keys
new file mode 100644
index 0000000..bc84ab1
--- /dev/null
+++ b/benchmarks/results/rename_keys
@@ -0,0 +1,10 @@
+=> benchmark: rename_keys
+=> host: andy-HP-ENVY-TS-15-Notebook-PC
+=> revision: b7df14f0aacb67d1e006bf1795e0ca45481bc925
+=> repo_state: clean
+
+Calculating -------------------------------------
+                       889.000  i/100ms
+-------------------------------------------------
+                          9.028k (± 3.9%) i/s -     45.339k
+********************************************************************************
diff --git a/benchmarks/results/symbolize_keys b/benchmarks/results/symbolize_keys
new file mode 100644
index 0000000..218d7b9
--- /dev/null
+++ b/benchmarks/results/symbolize_keys
@@ -0,0 +1,10 @@
+=> benchmark: symbolize_keys
+=> host: andy-HP-ENVY-TS-15-Notebook-PC
+=> revision: b7df14f0aacb67d1e006bf1795e0ca45481bc925
+=> repo_state: clean
+
+Calculating -------------------------------------
+                       899.000  i/100ms
+-------------------------------------------------
+                          9.164k (± 3.8%) i/s -     45.849k
+********************************************************************************
diff --git a/benchmarks/symbolize_keys b/benchmarks/symbolize_keys
new file mode 100755
index 0000000..90e716f
--- /dev/null
+++ b/benchmarks/symbolize_keys
@@ -0,0 +1,21 @@
+#!/usr/bin/env ruby
+# encoding: utf-8
+
+require_relative 'utils/setup.rb'
+
+mapper = build_mapper do
+  symbolize_keys true
+  attribute :name
+  attribute :email
+end
+
+tuples = create_tuple_collection(100) do
+  {
+    'name' => Faker::Name.name,
+    'email' => Faker::Internet.email
+  }
+end
+
+run('symbolize_keys') do |x|
+  x.report { mapper.call(tuples) }
+end
diff --git a/benchmarks/utils/setup.rb b/benchmarks/utils/setup.rb
new file mode 100644
index 0000000..d5a88f4
--- /dev/null
+++ b/benchmarks/utils/setup.rb
@@ -0,0 +1,84 @@
+require 'bundler'
+Bundler.require
+
+require 'socket'
+require 'ostruct'
+require 'benchmark/ips'
+require 'faker'
+require 'rom-mapper'
+
+begin
+  require 'byebug'
+rescue LoadError
+end
+
+# Enable and start GC before each job run. Disable GC afterwards.
+#
+# Inspired by https://www.omniref.com/ruby/2.2.1/symbols/Benchmark/bm?#annotation=4095926&line=182
+class GCSuite
+  def warming(*)
+    run_gc
+  end
+
+  def running(*)
+    run_gc
+  end
+
+  def warmup_stats(*)
+  end
+
+  def add_report(*)
+  end
+
+  private
+
+  def run_gc
+    GC.enable
+    GC.start
+    GC.disable
+  end
+end
+
+def hr
+  puts "*" * 80
+end
+
+def run(title, &block)
+  benchmark(title, &block)
+end
+
+def git_state
+  state = `git status -uno --porcelain`.split($/).reject do |line|
+    line.split(' ').last.start_with?('benchmarks/results/')
+  end
+
+  state.empty? ? 'clean' : "#{$/}  => #{state.join("#{$/}  => ")}"
+end
+
+def benchmark(title)
+  puts "=> benchmark: #{title}"
+  puts "=> host: #{Socket.gethostname}"
+  puts "=> revision: #{`git rev-parse HEAD`}"
+  puts "=> repo_state: #{git_state}"
+  puts $/
+  Benchmark.ips do |x|
+    x.config(suite: GCSuite.new)
+    yield x
+    x.compare!
+  end
+  hr
+end
+
+def create_mapper(&block)
+  Class.new(ROM::Mapper).tap do |mapper_klass|
+    mapper_klass.instance_eval(&block)
+  end
+end
+
+def build_mapper(&block)
+  create_mapper(&block).build
+end
+
+def create_tuple_collection(size, &block)
+  size.times.map { block.call }
+end
diff --git a/bin/benchmark b/bin/benchmark
new file mode 100755
index 0000000..26c7315
--- /dev/null
+++ b/bin/benchmark
@@ -0,0 +1,11 @@
+#!/usr/bin/env ruby
+# encoding: utf-8
+
+BENCHMARK_DIR = File.expand_path('../../benchmarks',  __FILE__)
+RESULTS_DIR = File.expand_path('../../benchmarks/results',  __FILE__)
+BENCHMARKS = Dir[File.join(BENCHMARK_DIR, '*')].select {|f| File.file?(f) }.sort
+RESULTS = BENCHMARKS.map { |bm| File.join(RESULTS_DIR, File.basename(bm)) }
+
+BENCHMARKS.zip(RESULTS).each do |benchmark, result|
+  system("#{benchmark} | tee #{result}")
+end