diff --git a/.buildpacks b/.buildpacks
index eb20a5d0..36201cad 100644
--- a/.buildpacks
+++ b/.buildpacks
@@ -1,2 +1,3 @@
 https://github.com/heroku/heroku-buildpack-ruby.git
 https://github.com/drogus/last-commit-sha-buildpack.git
+https://github.com/ryandotsmith/nginx-buildpack.git
diff --git a/.gitignore b/.gitignore
index bfabbb0a..e51c7335 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,9 +1,14 @@
 config/travis.yml
 config/database.yml
-.yardoc
-log/
-vendor
+config/nginx.conf
 config/skylight.yml
+
+tmp/
+log/
+logs/
+
+vendor
+
+.yardoc
 .coverage
 *.env
-tmp
diff --git a/Procfile b/Procfile
index cfffe7c2..a9a67e8c 100644
--- a/Procfile
+++ b/Procfile
@@ -1,3 +1,3 @@
-web: bundle exec je ./script/server
+web: ./script/server
 console: bundle exec je ./script/console
 sidekiq: bundle exec je sidekiq -c 4 -r ./lib/travis/sidekiq.rb -q build_cancellations, -q build_restarts, -q job_cancellations, -q job_restarts
diff --git a/bin/start-nginx b/bin/start-nginx
index f49c0be4..b0d1f589 100755
--- a/bin/start-nginx
+++ b/bin/start-nginx
@@ -1,3 +1,82 @@
-#!/bin/sh
+#!/usr/bin/env bash
 
-"$@"
+# make sure we kill all child processes once done
+trap '{ pkill -P $$; rm -f config/nginx.conf; exit 255; }' EXIT
+
+if [ -f bin/nginx ]; then
+  nginx=bin/nginx
+else
+  which nginx &>/dev/null || { echo "nginx not found" && exit 1; }
+  nginx=nginx
+fi
+
+psmgr=$tmp_dir/nginx-buildpack-wait
+rm -f $psmgr
+mkfifo $psmgr
+
+#Evaluate config to get $PORT
+erb config/nginx.conf.erb > config/nginx.conf
+
+n=1
+while getopts :f option ${@:1:2}
+do
+        case "${option}"
+        in
+                f) FORCE=$OPTIND; n=$((n+1));;
+        esac
+done
+
+#Initialize log directory.
+mkdir -p logs/nginx
+touch logs/nginx/access.log logs/nginx/error.log
+echo 'buildpack=nginx at=logs-initialized'
+
+#Start log redirection.
+(
+	#Redirect NGINX logs to stdout.
+	tail -qF -n 0 logs/nginx/*.log
+	echo 'logs' >$psmgr
+) &
+
+#Start App Server
+(
+	#Take the command passed to this bin and start it.
+	#E.g. bin/start-nginx bundle exec unicorn -c config/unicorn.rb
+        COMMAND=${@:$n}
+	echo "buildpack=nginx at=start-app cmd=$COMMAND"
+	$COMMAND
+	echo 'app' >$psmgr
+) &
+
+if [[ -z "$FORCE" ]]
+then
+	FILE="$tmp_dir/app-initialized"
+
+	#We block on app-initialized so that when NGINX binds to $PORT
+	#are app is ready for traffic.
+	while [[ ! -f "$FILE" ]]
+	do
+		echo 'buildpack=nginx at=app-initialization'
+		sleep 1
+	done
+	echo 'buildpack=nginx at=app-initialized'
+fi
+
+#Start NGINX
+(
+	#We expect nginx to run in foreground.
+	#We also expect a socket to be at $tmp_dir/nginx.socket.
+	echo 'buildpack=nginx at=nginx-start'
+	$nginx -p . -c config/nginx.conf
+	echo 'nginx' >$psmgr
+) &
+
+#This read will block the process waiting on a msg to be put into the fifo.
+#If any of the processes defined above should exit,
+#a msg will be put into the fifo causing the read operation
+#to un-block. The process putting the msg into the fifo
+#will use it's process name as a msg so that we can print the offending
+#process to stdout.
+read exit_process <$psmgr
+echo "buildpack=nginx at=exit process=$exit_process"
+exit 1
diff --git a/config/mime.types b/config/mime.types
new file mode 100644
index 00000000..18f31b3e
--- /dev/null
+++ b/config/mime.types
@@ -0,0 +1,76 @@
+
+types {
+    text/html                             html htm shtml;
+    text/css                              css;
+    text/xml                              xml;
+    text/cache-manifest                   manifest appcache;
+    image/gif                             gif;
+    image/jpeg                            jpeg jpg;
+    application/x-javascript              js;
+    application/atom+xml                  atom;
+    application/rss+xml                   rss;
+
+    text/mathml                           mml;
+    text/plain                            txt;
+    text/vnd.sun.j2me.app-descriptor      jad;
+    text/vnd.wap.wml                      wml;
+    text/x-component                      htc;
+
+    image/png                             png;
+    image/tiff                            tif tiff;
+    image/vnd.wap.wbmp                    wbmp;
+    image/x-icon                          ico;
+    image/x-jng                           jng;
+    image/x-ms-bmp                        bmp;
+    image/svg+xml                         svg;
+
+    application/java-archive              jar war ear;
+    application/mac-binhex40              hqx;
+    application/msword                    doc;
+    application/pdf                       pdf;
+    application/postscript                ps eps ai;
+    application/rtf                       rtf;
+    application/vnd.ms-excel              xls;
+    application/vnd.ms-powerpoint         ppt;
+    application/vnd.wap.wmlc              wmlc;
+    application/vnd.google-earth.kml+xml  kml;
+    application/vnd.google-earth.kmz      kmz;
+    application/x-7z-compressed           7z;
+    application/x-cocoa                   cco;
+    application/x-java-archive-diff       jardiff;
+    application/x-java-jnlp-file          jnlp;
+    application/x-makeself                run;
+    application/x-perl                    pl pm;
+    application/x-pilot                   prc pdb;
+    application/x-rar-compressed          rar;
+    application/x-redhat-package-manager  rpm;
+    application/x-sea                     sea;
+    application/x-shockwave-flash         swf;
+    application/x-stuffit                 sit;
+    application/x-tcl                     tcl tk;
+    application/x-x509-ca-cert            der pem crt;
+    application/x-xpinstall               xpi;
+    application/xhtml+xml                 xhtml;
+    application/zip                       zip;
+
+    application/octet-stream              bin exe dll;
+    application/octet-stream              deb;
+    application/octet-stream              dmg;
+    application/octet-stream              eot;
+    application/octet-stream              iso img;
+    application/octet-stream              msi msp msm;
+
+    audio/midi                            mid midi kar;
+    audio/mpeg                            mp3;
+    audio/ogg                             ogg;
+    audio/x-realaudio                     ra;
+
+    video/3gpp                            3gpp 3gp;
+    video/mpeg                            mpeg mpg;
+    video/quicktime                       mov;
+    video/x-flv                           flv;
+    video/x-mng                           mng;
+    video/x-ms-asf                        asx asf;
+    video/x-ms-wmv                        wmv;
+    video/x-msvideo                       avi;
+}
diff --git a/config/nginx.conf.erb b/config/nginx.conf.erb
new file mode 100644
index 00000000..8866fd5a
--- /dev/null
+++ b/config/nginx.conf.erb
@@ -0,0 +1,45 @@
+daemon off;
+#Heroku dynos have at least 4 cores.
+worker_processes <%= ENV['NGINX_WORKERS'] || ENV['WEB_CONCURRENCY'] || 4 %>;
+
+events {
+	<% if `uname` != "Darwin\n" %>use epoll;<% end %>
+	accept_mutex on;
+	worker_connections 1024;
+}
+
+http {
+        gzip on;
+        gzip_comp_level 2;
+        gzip_min_length 512;
+
+	server_tokens off;
+
+	log_format l2met 'measure#nginx.service=$request_time request_id=$http_x_request_id';
+	access_log logs/nginx/access.log l2met;
+	error_log logs/nginx/error.log;
+
+	include mime.types;
+	default_type application/octet-stream;
+	sendfile on;
+
+	#Must read the body in 5 seconds.
+	client_body_timeout 5;
+
+	upstream app_server {
+		server unix:<%= ENV["tmp_dir"] %>/nginx.socket fail_timeout=0;
+ 	}
+
+	server {
+		listen <%= ENV["PORT"] %>;
+		server_name _;
+		keepalive_timeout 5;
+
+		location / {
+			proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+			proxy_set_header Host $http_host;
+			proxy_redirect off;
+			proxy_pass http://app_server;
+		}
+	}
+}
diff --git a/config/puma-config.rb b/config/puma-config.rb
index 38d7628e..1c15535d 100644
--- a/config/puma-config.rb
+++ b/config/puma-config.rb
@@ -2,8 +2,8 @@ root = File.expand_path('../..', __FILE__)
 
 rackup "#{root}/config.ru"
 
-bind 'unix:///tmp/nginx.socket'
-
+tmp_dir = ENV.fetch("tmp_dir", "/tmp")
+bind "unix://#{tmp_dir}/nginx.socket"
 environment ENV['RACK_ENV'] || 'development'
 
 threads 0, 16
diff --git a/config/ruby_config.sh b/config/ruby_config.sh
new file mode 100644
index 00000000..3edf1db6
--- /dev/null
+++ b/config/ruby_config.sh
@@ -0,0 +1,7 @@
+#!/bin/bash
+export RUBY_HEAP_MIN_SLOTS=800000
+export RUBY_GC_HEAP_INIT_SLOTS=$RUBY_HEAP_MIN_SLOTS
+export RUBY_GC_MALLOC_LIMIT=59000000
+export RUBY_HEAP_SLOTS_INCREMENT=10000
+export RUBY_HEAP_SLOTS_GROWTH_FACTOR=1
+export RUBY_HEAP_FREE_MIN=100000
diff --git a/config/unicorn.rb b/config/unicorn.rb
index 1e9da525..463a017c 100644
--- a/config/unicorn.rb
+++ b/config/unicorn.rb
@@ -1,19 +1,16 @@
 # http://michaelvanrooijen.com/articles/2011/06/01-more-concurrency-on-a-single-heroku-dyno-with-the-new-celadon-cedar-stack/
 
-worker_processes 4 # amount of unicorn workers to spin up
-timeout 30         # restarts workers that hang for 15 seconds
+worker_processes Integer(ENV.fetch('WEB_CONCURRENCY')) # amount of unicorn workers to spin up
+timeout 30 # restarts workers that hang for 30 seconds
 
-listen '/tmp/nginx.socket', backlog: 1024
+tmp_dir = ENV.fetch("tmp_dir", "/tmp")
+listen File.expand_path("nginx.socket", tmp_dir), backlog: 1024
 
 require 'fileutils'
-before_fork do |server,worker|
-  FileUtils.touch('/tmp/app-initialized')
-end
+before_fork do |server, worker|
+  # preload travis so we can have copy on write
+  require 'travis/api/app'
 
-before_exec do |server|
-  ENV['RUBY_HEAP_MIN_SLOTS']=800000
-  ENV['RUBY_GC_MALLOC_LIMIT']=59000000
-  ENV['RUBY_HEAP_SLOTS_INCREMENT']=10000
-  ENV['RUBY_HEAP_SLOTS_GROWTH_FACTOR']=1
-  ENV['RUBY_HEAP_FREE_MIN']=100000
+  # signal to nginx we're ready
+  FileUtils.touch("#{tmp_dir}/app-initialized")
 end
diff --git a/lib/travis/api/app/endpoint/home.rb b/lib/travis/api/app/endpoint/home.rb
index c91612cf..ecdfbf82 100644
--- a/lib/travis/api/app/endpoint/home.rb
+++ b/lib/travis/api/app/endpoint/home.rb
@@ -49,6 +49,18 @@ class Travis::Api::App
       get '/config' do
         { config: settings.client_config }
       end
+
+      deploy_sha = File.read(".deploy-sha") if File.exist?(".deploy-sha")
+      sys_info   = {
+        web_concurrency: ENV['WEB_CONCURRENCY'],
+        ulimit: `echo "ulimit -u" | bash`.to_i,
+        dyno: ENV['DYNO'],
+        deploy_sha: deploy_sha
+      }
+
+      get '/sysinfo' do
+        sys_info
+      end
     end
   end
 end
diff --git a/lib/travis/api/attack.rb b/lib/travis/api/attack.rb
index 9d9231e1..4d91ec31 100644
--- a/lib/travis/api/attack.rb
+++ b/lib/travis/api/attack.rb
@@ -60,16 +60,16 @@ class Rack::Attack
   end
 
   ###
-  # Throttle:  unauthenticated requests - 50 per minute
+  # Throttle:  unauthenticated requests - 500 per minute
   # Scoped by: IP address
-  throttle('req/ip/1min', limit: 50, period: 1.minute) do |request|
+  throttle('req/ip/1min', limit: 500, period: 1.minute) do |request|
     request.ip unless request.authenticated?
   end
 
   ###
-  # Throttle:  authenticated requests - 200 per minute
+  # Throttle:  authenticated requests - 2000 per minute
   # Scoped by: access token
-  throttle('req/token/1min', limit: 200, period: 1.minute) do |request|
+  throttle('req/token/1min', limit: 2000, period: 1.minute) do |request|
     request.identifier
   end
 
diff --git a/lib/travis/api/v3/models/account.rb b/lib/travis/api/v3/models/account.rb
index 53f45fd0..aff1a510 100644
--- a/lib/travis/api/v3/models/account.rb
+++ b/lib/travis/api/v3/models/account.rb
@@ -40,4 +40,4 @@ module Travis::API::V3
     alias_method :educational, :educational?
     alias_method :subscribed,  :subscribed?
   end
-end
\ No newline at end of file
+end
diff --git a/lib/travis/api/v3/queries/branches.rb b/lib/travis/api/v3/queries/branches.rb
index c368fa7d..a2c8e1c3 100644
--- a/lib/travis/api/v3/queries/branches.rb
+++ b/lib/travis/api/v3/queries/branches.rb
@@ -1,10 +1,33 @@
 module Travis::API::V3
   class Queries::Branches < Query
-    sortable_by :name, last_build: "builds.started_at".freeze
-    default_sort "last_build:desc"
+    params :exists_on_github, prefix: :branch
+
+    sortable_by :name,
+      last_build:       "builds.started_at".freeze,
+      exists_on_github: sort_condition(:exists_on_github),
+      default_branch:   sort_condition(name: "repositories.default_branch")
+
+    default_sort "default_branch,exists_on_github,last_build:desc"
 
     def find(repository)
-      sort repository.branches
+      sort(filter(repository.branches), repository: repository)
+    end
+
+    def sort_by(collection, field, repository: nil, **options)
+      return super unless field == "default_branch".freeze
+
+      if repository
+        options[:sql] = sort_condition(name: quote(repository.default_branch_name))
+      else
+        collection    = collection.joins(:repository)
+      end
+
+      super(collection, field, **options)
+    end
+
+    def filter(list)
+      list = list.where(exists_on_github: bool(exists_on_github)) unless exists_on_github.nil?
+      list
     end
   end
 end
diff --git a/lib/travis/api/v3/query.rb b/lib/travis/api/v3/query.rb
index 488018bf..e4ea4f09 100644
--- a/lib/travis/api/v3/query.rb
+++ b/lib/travis/api/v3/query.rb
@@ -48,6 +48,13 @@ module Travis::API::V3
       mapping.each { |key, value| sort_by[key.to_s]   = prefix(value) }
     end
 
+    def self.sort_condition(condition)
+      if condition.is_a? Hash
+        condition = condition.map { |e| e.map { |v| prefix(v) }.join(" = ".freeze) }.join(" and ".freeze)
+      end
+      "(case when #{prefix(condition)} then 1 else 2 end)"
+    end
+
     def self.sortable?
       !sort_by.empty?
     end
@@ -111,14 +118,14 @@ module Travis::API::V3
       value.split(?,.freeze)
     end
 
-    def sort(collection)
+    def sort(collection, **options)
       return collection unless sort_by = params["sort_by".freeze] || self.class.default_sort and not sort_by.empty?
       first = true
       list(sort_by).each do |field_with_order|
         field, order = field_with_order.split(?:.freeze, 2)
         order      ||= "asc".freeze
         if sort_by? field, order
-          collection = sort_by(collection, field, order: order, first: first)
+          collection = sort_by(collection, field, order: order, first: first, **options)
           first      = false
         else
           ignored_value("sort_by".freeze, field_with_order, reason: "not a valid sort mode".freeze)
@@ -132,9 +139,9 @@ module Travis::API::V3
       self.class.sort_by.include?(field)
     end
 
-    def sort_by(collection, field, order: nil, first: false)
+    def sort_by(collection, field, order: nil, first: false, sql: nil, **)
       raise ArgumentError, 'cannot sort by that' unless sort_by?(field, order)
-      actual = self.class.sort_by.fetch(field)
+      actual = sql || self.class.sort_by.fetch(field)
       line   = "#{actual} #{order.upcase}"
 
       if sort_join?(collection, actual)
@@ -150,6 +157,14 @@ module Travis::API::V3
       !collection.reflect_on_association(field.to_sym).nil?
     end
 
+    def sort_condition(*args)
+      self.class.sort_condition(*args)
+    end
+
+    def quote(value)
+      ActiveRecord::Base.connection.quote(value)
+    end
+
     def user_condition(value)
       case value
       when String       then { login: value    }
diff --git a/lib/travis/api/v3/services/branches/find.rb b/lib/travis/api/v3/services/branches/find.rb
index cd618c70..34cf0ef1 100644
--- a/lib/travis/api/v3/services/branches/find.rb
+++ b/lib/travis/api/v3/services/branches/find.rb
@@ -1,5 +1,6 @@
 module Travis::API::V3
   class Services::Branches::Find < Service
+    params :exists_on_github, prefix: :branch
     paginate
 
     def run!
diff --git a/script/server b/script/server
index 01320b42..3afd1c27 100755
--- a/script/server
+++ b/script/server
@@ -1,8 +1,26 @@
 #!/usr/bin/env bash
 cd "$(dirname "$0")/.."
-[ $PORT ]     || PORT=3000
-[ $RACK_ENV ] || RACK_ENV=development
 
-cmd="ruby -I lib -S bundle exec ruby -I lib -S unicorn config.ru -p $PORT -E $RACK_ENV -c config/unicorn.rb"
-[[ $RACK_ENV == "development" ]] && exec rerun "$cmd -l 127.0.0.1:$PORT"
+. config/ruby_config.sh
+
+[ $PORT ]            || export PORT=3000
+[ $RACK_ENV ]        || export RACK_ENV=development
+[ $WEB_CONCURRENCY ] || export WEB_CONCURRENCY=$(script/web_concurrency)
+[ $NGINX_WORKERS ]   || export NGINX_WORKERS=$(script/web_concurrency --nginx)
+
+echo "port=$PORT rack_env=$RACK_ENV web_concurrency=$WEB_CONCURRENCY nginx_workers=$NGINX_WORKERS" >&2
+
+ruby="ruby -I lib -S"
+bexc="$ruby bundle exec"
+
+if [[ $RACK_ENV == "production" ]]; then
+  export tmp_dir=/tmp
+else
+  mkdir -p tmp
+  export tmp_dir=./tmp
+fi
+
+cmd="unicorn config.ru -E $RACK_ENV -c config/unicorn.rb"
+[[ $RACK_ENV == "development" ]] && cmd="rerun -b -- $cmd"
+cmd="bin/start-nginx $bexec je $cmd"
 exec $cmd
diff --git a/script/web_concurrency b/script/web_concurrency
new file mode 100755
index 00000000..1e7bdec1
--- /dev/null
+++ b/script/web_concurrency
@@ -0,0 +1,25 @@
+#!/bin/bash
+
+if [[ "$RACK_ENV" == "development" ]]; then
+  echo -n 2
+  exit 0
+fi
+
+
+if [[ "$1" == "--nginx" ]]; then
+  case $(ulimit -u) in
+    256)    echo -n 1; exit 0;; # Standard 1x, 512MB
+    512)    echo -n 2; exit 0;; # Standard 2x, 1GB
+    16384)  echo -n 4; exit 0;; # Performance M, 2.5GB
+    32768)  echo -n 4; exit 0;; # Performance L, 14GB
+  esac
+else
+  case $(ulimit -u) in
+    256)    echo -n 2;  exit 0;; # Standard 1x, 512MB
+    512)    echo -n 4;  exit 0;; # Standard 2x, 1GB
+    16384)  echo -n 10; exit 0;; # Performance M, 2.5GB
+    32768)  echo -n 50; exit 0;; # Performance L, 14GB
+  esac
+fi
+
+echo -n 4
diff --git a/spec/v3/services/branches/find_spec.rb b/spec/v3/services/branches/find_spec.rb
index 6a38111b..3a930db5 100644
--- a/spec/v3/services/branches/find_spec.rb
+++ b/spec/v3/services/branches/find_spec.rb
@@ -132,6 +132,20 @@ describe Travis::API::V3::Services::Branches::Find do
     }
   end
 
+  describe "filtering by exists_on_github" do
+    describe "false" do
+      before     { get("/v3/repo/#{repo.id}/branches?branch.exists_on_github=false") }
+      example    { expect(last_response).to be_ok }
+      example    { expect(parsed_body["branches"]).to be_empty }
+    end
+
+    describe "true" do
+      before     { get("/v3/repo/#{repo.id}/branches?branch.exists_on_github=true") }
+      example    { expect(last_response).to be_ok }
+      example    { expect(parsed_body["branches"]).not_to be_empty }
+    end
+  end
+
   describe "sorting by name" do
     before  { get("/v3/repo/#{repo.id}/branches?sort_by=name&limit=1") }
     example { expect(last_response).to be_ok }
@@ -176,6 +190,50 @@ describe Travis::API::V3::Services::Branches::Find do
     }
   end
 
+  describe "sorting by exists_on_github" do
+    before  { get("/v3/repo/#{repo.id}/branches?sort_by=exists_on_github&limit=1") }
+    example { expect(last_response).to be_ok }
+    example { expect(parsed_body["@pagination"]).to be == {
+        "limit"            => 1,
+        "offset"           => 0,
+        "count"            => 1,
+        "is_first"         => true,
+        "is_last"          => true,
+        "next"             => nil,
+        "prev"             => nil,
+        "first"            => {
+          "@href"          => "/v3/repo/#{repo.id}/branches?sort_by=exists_on_github&limit=1",
+          "offset"         => 0,
+          "limit"          => 1 },
+        "last"             => {
+          "@href"          => "/v3/repo/#{repo.id}/branches?sort_by=exists_on_github&limit=1",
+          "offset"         => 0,
+          "limit"          => 1 }}
+    }
+  end
+
+  describe "sorting by default_branch" do
+    before  { get("/v3/repo/#{repo.id}/branches?sort_by=default_branch&limit=1") }
+    example { expect(last_response).to be_ok }
+    example { expect(parsed_body["@pagination"]).to be == {
+        "limit"            => 1,
+        "offset"           => 0,
+        "count"            => 1,
+        "is_first"         => true,
+        "is_last"          => true,
+        "next"             => nil,
+        "prev"             => nil,
+        "first"            => {
+          "@href"          => "/v3/repo/#{repo.id}/branches?sort_by=default_branch&limit=1",
+          "offset"         => 0,
+          "limit"          => 1 },
+        "last"             => {
+          "@href"          => "/v3/repo/#{repo.id}/branches?sort_by=default_branch&limit=1",
+          "offset"         => 0,
+          "limit"          => 1 }}
+    }
+  end
+
   describe "sorting by unknown sort field" do
     before  { get("/v3/repo/#{repo.id}/branches?sort_by=name:desc,foo&limit=1") }
     example { expect(last_response).to be_ok }