diff --git a/Gemfile b/Gemfile
index ae404d8..0da950b 100644
--- a/Gemfile
+++ b/Gemfile
@@ -100,8 +100,7 @@ end
 
 group :heroku, :production do
   gem 'rails_12factor', require: ENV.key?("HEROKU")
-  gem 'unicorn', require: false, platform: 'ruby'
-  gem 'unicorn-worker-killer'
+  gem 'puma'
 end
 
 gem 'therubyracer', platform: :ruby # C Ruby (MRI) or Rubinius, but NOT Windows
diff --git a/Gemfile.lock b/Gemfile.lock
index 8cf2947..1b375e6 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -134,7 +134,6 @@ GEM
       multi_json
     font-awesome-rails (4.2.0.0)
       railties (>= 3.2, < 5.0)
-    get_process_mem (0.2.0)
     globalid (0.3.6)
       activesupport (>= 4.1.0)
     haml (4.0.6)
@@ -165,7 +164,6 @@ GEM
     kaminari (0.16.3)
       actionpack (>= 3.0.0)
       activesupport (>= 3.0.0)
-    kgio (2.9.3)
     launchy (2.4.3)
       addressable (~> 2.3)
     launchy (2.4.3-java)
@@ -258,6 +256,7 @@ GEM
       pry (~> 0.10)
     pry-rails (0.3.4)
       pry (>= 0.9.10)
+    puma (2.15.3)
     quiet_assets (1.1.0)
       railties (>= 3.1, < 5.0)
     rack (1.6.4)
@@ -300,7 +299,6 @@ GEM
       rake (>= 0.8.7)
       thor (>= 0.18.1, < 2.0)
     rainbow (2.0.0)
-    raindrops (0.13.0)
     rake (10.4.2)
     ref (1.0.5)
     request_store (1.1.0)
@@ -398,13 +396,6 @@ GEM
       unf_ext
     unf (0.1.4-java)
     unf_ext (0.0.7.1)
-    unicorn (4.9.0)
-      kgio (~> 2.6)
-      rack
-      raindrops (~> 0.7)
-    unicorn-worker-killer (0.4.3)
-      get_process_mem (~> 0)
-      unicorn (~> 4)
     useragent (0.14.0)
     warden (1.2.3)
       rack (>= 1.0)
@@ -465,6 +456,7 @@ DEPENDENCIES
   poltergeist
   pry-byebug
   pry-rails
+  puma
   quiet_assets
   rack-ssl
   rack-ssl-enforcer
@@ -483,8 +475,6 @@ DEPENDENCIES
   timecop
   uglifier
   underscore-rails
-  unicorn
-  unicorn-worker-killer
   useragent
   xmpp4r
   yajl-ruby
diff --git a/Procfile b/Procfile
index 8fd8940..e91374b 100644
--- a/Procfile
+++ b/Procfile
@@ -1 +1 @@
-web: bundle exec unicorn -c ./config/unicorn.default.rb
+web: bundle exec puma -C config/puma.default.rb
diff --git a/config.ru b/config.ru
index bde969b..76d9bb0 100644
--- a/config.ru
+++ b/config.ru
@@ -1,13 +1,3 @@
-if ENV['USE_UNICORN_WORKER_KILLER']
-  require 'unicorn/worker_killer'
-  max_request_min =  ENV['KILL_ON_REQUEST_COUNT_MIN'].to_i || 3072
-  max_request_max =  ENV['KILL_ON_REQUEST_COUNT_MAX'].to_i || 4096
-  use Unicorn::WorkerKiller::MaxRequests, max_request_min, max_request_max
-  oom_min = ((ENV['KILL_ON_RSS_MIN'].to_i || 250) * (1024**2))
-  oom_max = ((ENV['KILL_ON_RSS_MAX'].to_i || 300) * (1024**2))
-  use Unicorn::WorkerKiller::Oom, oom_min, oom_max
-end
-
 # This file is used by Rack-based servers to start the application.
 
 require ::File.expand_path('../config/environment', __FILE__)
diff --git a/config/puma.default.rb b/config/puma.default.rb
new file mode 100644
index 0000000..765116b
--- /dev/null
+++ b/config/puma.default.rb
@@ -0,0 +1,19 @@
+# https://devcenter.heroku.com/articles/deploying-rails-applications-with-the-puma-web-server
+
+workers Integer(ENV['WEB_CONCURRENCY'] || 2)
+threads_count = Integer(ENV['MAX_THREADS'] || 5)
+threads threads_count, threads_count
+
+preload_app!
+
+rackup      DefaultRackup
+port        ENV['PORT']     || 3000
+environment ENV['RACK_ENV'] || 'development'
+
+on_worker_boot do
+  # Worker specific setup for Rails 4.1+
+  # See: https://devcenter.heroku.com/articles/deploying-rails-applications-with-the-puma-web-server#on-worker-boot
+  ActiveSupport.on_load(:active_record) do
+    ActiveRecord::Base.establish_connection
+  end
+end
diff --git a/config/unicorn.default.rb b/config/unicorn.default.rb
deleted file mode 100644
index b97ef26..0000000
--- a/config/unicorn.default.rb
+++ /dev/null
@@ -1,31 +0,0 @@
-# http://michaelvanrooijen.com/articles/2011/06/01-more-concurrency-on-a-single-heroku-dyno-with-the-new-celadon-cedar-stack/
-
-worker_processes 3 # amount of unicorn workers to spin up
-timeout 30         # restarts workers that hang for 30 seconds
-preload_app true
-listen ENV['PORT'] || 8080
-pid ENV['UNICORN_PID'] if ENV['UNICORN_PID']
-
-# Taken from github: https://github.com/blog/517-unicorn
-# Though everyone uses pretty miuch the same code
-before_fork do |server, _worker|
-  ##
-  # When sent a USR2, Unicorn will suffix its pidfile with .oldbin and
-  # immediately start loading up a new version of itself (loaded with a new
-  # version of our app). When this new Unicorn is completely loaded
-  # it will begin spawning workers. The first worker spawned will check to
-  # see if an .oldbin pidfile exists. If so, this means we've just booted up
-  # a new Unicorn and need to tell the old one that it can now die. To do so
-  # we send it a QUIT.
-  #
-  # Using this method we get 0 downtime deploys.
-
-  old_pid = "#{server.config[:pid]}.oldbin"
-  if File.exist?(old_pid) && server.pid != old_pid
-    begin
-      Process.kill("QUIT", File.read(old_pid).to_i)
-    rescue Errno::ENOENT, Errno::ESRCH
-      warn "Unicorn: master process already killed, no problem"
-    end
-  end
-end
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