diff --git a/app/models/backtrace.rb b/app/models/backtrace.rb
new file mode 100644
index 0000000..570aa94
--- /dev/null
+++ b/app/models/backtrace.rb
@@ -0,0 +1,32 @@
+class Backtrace
+  include Mongoid::Document
+  include Mongoid::Timestamps
+
+  field :fingerprint
+  index :fingerprint
+
+  has_many :notices
+  embeds_many :lines, :class_name => "BacktraceLine"
+
+  after_initialize :generate_fingerprint
+
+  def self.find_or_create(attributes = {})
+    new(attributes).similar || create(attributes)
+  end
+
+  def similar
+    Backtrace.first(:conditions => { :fingerprint => fingerprint } )
+  end
+
+  def raw=(raw)
+    raw.each do |raw_line|
+      lines << BacktraceLine.new(BacktraceLineNormalizer.new(raw_line).call)
+    end
+  end
+
+  private
+  def generate_fingerprint
+    self.fingerprint = Digest::SHA1.hexdigest(lines.join)
+  end
+
+end
diff --git a/app/models/backtrace_line.rb b/app/models/backtrace_line.rb
new file mode 100644
index 0000000..f59c4e1
--- /dev/null
+++ b/app/models/backtrace_line.rb
@@ -0,0 +1,10 @@
+class BacktraceLine
+  include Mongoid::Document
+
+  field :number, type: Integer
+  field :file
+  field :method
+
+  embedded_in :backtrace
+end
+
diff --git a/app/models/backtrace_line_normalizer.rb b/app/models/backtrace_line_normalizer.rb
new file mode 100644
index 0000000..50b6fe6
--- /dev/null
+++ b/app/models/backtrace_line_normalizer.rb
@@ -0,0 +1,11 @@
+class BacktraceLineNormalizer
+  def initialize(raw_line)
+    @raw_line = raw_line
+  end
+
+  def call
+    @raw_line.merge! 'file' => "[unknown source]" if @raw_line['file'].blank?
+    @raw_line.merge! 'method' => @raw_line['method'].gsub(/[0-9_]{10,}+/, "__FRAGMENT__")
+  end
+
+end
diff --git a/app/models/error_report.rb b/app/models/error_report.rb
index 01e9fd6..365cc3b 100644
--- a/app/models/error_report.rb
+++ b/app/models/error_report.rb
@@ -2,7 +2,7 @@ require 'digest/sha1'
 require 'hoptoad_notifier'
 
 class ErrorReport
-  attr_reader :error_class, :message, :backtrace, :request, :server_environment, :api_key, :notifier, :user_attributes, :current_user
+  attr_reader :error_class, :message, :request, :server_environment, :api_key, :notifier, :user_attributes, :current_user
 
   def initialize(xml_or_attributes)
     @attributes = (xml_or_attributes.is_a?(String) ? Hoptoad.parse_xml!(xml_or_attributes) : xml_or_attributes).with_indifferent_access
@@ -29,11 +29,15 @@ class ErrorReport
     @app ||= App.find_by_api_key!(api_key)
   end
 
+  def backtrace
+    @normalized_backtrace ||= Backtrace.find_or_create(:raw => @backtrace)
+  end
+
   def generate_notice!
     notice = Notice.new(
       :message => message,
       :error_class => error_class,
-      :backtrace => backtrace,
+      :backtrace_id => backtrace.id,
       :request => request,
       :server_environment => server_environment,
       :notifier => notifier,
@@ -55,7 +59,7 @@ class ErrorReport
   private
   def fingerprint_source
     {
-      :backtrace => normalized_backtrace.to_s,
+      :backtrace => backtrace.lines[0..3],
       :error_class => error_class,
       :component => component,
       :action => action,
@@ -64,11 +68,5 @@ class ErrorReport
     }
   end
 
-  def normalized_backtrace
-    backtrace[0...3].map do |trace|
-      trace.merge 'method' => trace['method'].gsub(/[0-9_]{10,}+/, "__FRAGMENT__")
-    end
-  end
-
 end
 
diff --git a/app/models/notice.rb b/app/models/notice.rb
index 9afd13c..f848f2f 100644
--- a/app/models/notice.rb
+++ b/app/models/notice.rb
@@ -6,15 +6,16 @@ class Notice
   include Mongoid::Timestamps
 
   field :message
-  field :backtrace, :type => Array
   field :server_environment, :type => Hash
   field :request, :type => Hash
   field :notifier, :type => Hash
   field :user_attributes, :type => Hash
   field :current_user, :type => Hash
   field :error_class
+  delegate :lines, :to => :backtrace, :prefix => true
 
   belongs_to :err
+  belongs_to :backtrace, :index => true
   index :created_at
   index(
     [
@@ -28,7 +29,7 @@ class Notice
   before_save :sanitize
   before_destroy :decrease_counter_cache, :remove_cached_attributes_from_problem
 
-  validates_presence_of :backtrace, :server_environment, :notifier
+  validates_presence_of :server_environment, :notifier, :backtrace
 
   scope :ordered, order_by(:created_at.asc)
   scope :reverse_ordered, order_by(:created_at.desc)
@@ -92,15 +93,7 @@ class Notice
 
   # Backtrace containing only files from the app itself (ignore gems)
   def app_backtrace
-    backtrace.select { |l| l && l['file'] && l['file'].include?("[PROJECT_ROOT]") }
-  end
-
-  def backtrace
-    # If gems are vendored into project, treat vendored gem dir as [GEM_ROOT]
-    (read_attribute(:backtrace) || []).map do |line|
-      # Changes "[PROJECT_ROOT]/rubygems/ruby/1.9.1/gems" to "[GEM_ROOT]/gems"
-      line.merge 'file' => line['file'].to_s.gsub(/\[PROJECT_ROOT\]\/.*\/ruby\/[0-9.]+\/gems/, '[GEM_ROOT]/gems')
-    end
+    backtrace_lines.select { |l| l && l['file'] && l['file'].include?("[PROJECT_ROOT]") }
   end
 
   protected
@@ -129,8 +122,6 @@ class Notice
     [:server_environment, :request, :notifier].each do |h|
       send("#{h}=",sanitize_hash(send(h)))
     end
-    # Set unknown backtrace files
-    read_attribute(:backtrace).each{|line| line['file'] = "[unknown source]" if line['file'].blank? }
   end
 
   def sanitize_hash(h)
diff --git a/app/views/issue_trackers/fogbugz_body.txt.erb b/app/views/issue_trackers/fogbugz_body.txt.erb
index 56195b9..ff1a9bd 100644
--- a/app/views/issue_trackers/fogbugz_body.txt.erb
+++ b/app/views/issue_trackers/fogbugz_body.txt.erb
@@ -19,7 +19,7 @@
   <%= pretty_hash(notice.session) %>
 
   Backtrace
-  <% for line in notice.backtrace %>
+  <% for line in notice.backtrace_lines %>
     <%= line['number'] %>:  <%= line['file'].to_s.sub(/^\[PROJECT_ROOT\]/, '') %>
   <% end %>
 
diff --git a/app/views/issue_trackers/github_issues_body.txt.erb b/app/views/issue_trackers/github_issues_body.txt.erb
index b0edcd5..f3efb45 100644
--- a/app/views/issue_trackers/github_issues_body.txt.erb
+++ b/app/views/issue_trackers/github_issues_body.txt.erb
@@ -27,7 +27,7 @@
 
 ## Backtrace ##
 ```
-<% for line in notice.backtrace %><%= line['number'] %>:  <%= line['file'].to_s.sub(/^\[PROJECT_ROOT\]/, '') %> -> **<%= line['method'] %>**
+<% for line in notice.backtrace_lines %><%= line['number'] %>:  <%= line['file'].to_s.sub(/^\[PROJECT_ROOT\]/, '') %> -> **<%= line['method'] %>**
 <% end %>
 ```
 
diff --git a/app/views/issue_trackers/lighthouseapp_body.txt.erb b/app/views/issue_trackers/lighthouseapp_body.txt.erb
index 612047c..a5313e9 100644
--- a/app/views/issue_trackers/lighthouseapp_body.txt.erb
+++ b/app/views/issue_trackers/lighthouseapp_body.txt.erb
@@ -23,7 +23,7 @@
 
   ## Backtrace ##
   <code>
-  <% for line in notice.backtrace %><%= line['number'] %>:  <%= line['file'].to_s.sub(/^\[PROJECT_ROOT\]/, '') %> -> **<%= line['method'] %>**
+  <% for line in notice.backtrace_lines %><%= line['number'] %>:  <%= line['file'].to_s.sub(/^\[PROJECT_ROOT\]/, '') %> -> **<%= line['method'] %>**
   <% end %>
   </code>
 
diff --git a/app/views/issue_trackers/pivotal_body.txt.erb b/app/views/issue_trackers/pivotal_body.txt.erb
index b2fadc5..515a347 100644
--- a/app/views/issue_trackers/pivotal_body.txt.erb
+++ b/app/views/issue_trackers/pivotal_body.txt.erb
@@ -12,6 +12,6 @@ See this exception on Errbit: <%= app_problem_url problem.app, problem %>
     <%= pretty_hash notice.session %>
 
     Backtrace:
-    <%= notice.backtrace[0..4].map { |line| "#{line['number']}: #{line['file'].to_s.sub(/^\[PROJECT_ROOT\]/, '')} -> *#{line['method']}*" }.join "\n" %>
+    <%= notice.backtrace_lines[0..4].map { |line| "#{line['number']}: #{line['file'].to_s.sub(/^\[PROJECT_ROOT\]/, '')} -> *#{line['method']}*" }.join "\n" %>
 <% end %>
 
diff --git a/app/views/issue_trackers/textile_body.txt.erb b/app/views/issue_trackers/textile_body.txt.erb
index c65d886..6dd6192 100644
--- a/app/views/issue_trackers/textile_body.txt.erb
+++ b/app/views/issue_trackers/textile_body.txt.erb
@@ -32,7 +32,7 @@ h2. Session
 h2. Backtrace
 
 | Line | File | Method |
-<% for line in notice.backtrace %>| <%= line['number'] %> | <%= line['file'].to_s.sub(/^\[PROJECT_ROOT\]/, '') %> | *<%= line['method'] %>* |
+<% for line in notice.backtrace_lines %>| <%= line['number'] %> | <%= line['file'].to_s.sub(/^\[PROJECT_ROOT\]/, '') %> | *<%= line['method'] %>* |
 <% end %>
 
 h2. Environment
diff --git a/app/views/mailer/err_notification.html.haml b/app/views/mailer/err_notification.html.haml
index 9884876..d6fbb23 100644
--- a/app/views/mailer/err_notification.html.haml
+++ b/app/views/mailer/err_notification.html.haml
@@ -36,7 +36,7 @@
                 - if @notice.request['url'].present?
                   = link_to @notice.request['url'], @notice.request['url']
               %p.heading BACKTRACE:
-              - @notice.backtrace.map {|l| l ? "#{l['file']}:#{l['number']}" : nil }.compact.each do |line|
+              - @notice.backtrace_lines.map {|l| l ? "#{l['file']}:#{l['number']}" : nil }.compact.each do |line|
                 %p.backtrace= line
               %br
 
diff --git a/app/views/mailer/err_notification.text.erb b/app/views/mailer/err_notification.text.erb
index 22acf3e..5c2151b 100644
--- a/app/views/mailer/err_notification.text.erb
+++ b/app/views/mailer/err_notification.text.erb
@@ -26,7 +26,7 @@ URL:
 
 BACKTRACE:
 
-<% @notice.backtrace.map {|l| l ? "#{l['file']}:#{l['number']}" : nil }.compact.each do |line| %>
+<% @notice.backtrace_lines.map {|l| l ? "#{l['file']}:#{l['number']}" : nil }.compact.each do |line| %>
   <%= line %>
 <% end %>
 
diff --git a/app/views/notices/_atom_entry.html.haml b/app/views/notices/_atom_entry.html.haml
index 942fcf7..8021c50 100644
--- a/app/views/notices/_atom_entry.html.haml
+++ b/app/views/notices/_atom_entry.html.haml
@@ -22,7 +22,7 @@
 
 %h3 Backtrace
 %table
-  - for line in notice.backtrace
+  - for line in notice.backtrace_lines
     %tr
       %td
         = "#{line['number']}:"
diff --git a/app/views/problems/show.html.haml b/app/views/problems/show.html.haml
index 596964d..4326e61 100644
--- a/app/views/problems/show.html.haml
+++ b/app/views/problems/show.html.haml
@@ -63,7 +63,7 @@
 
   #backtrace
     %h3 Backtrace
-    = render 'notices/backtrace', :lines => @notice.backtrace
+    = render 'notices/backtrace', :lines => @notice.backtrace_lines
 
   - if @notice.user_attributes.present?
     #user_attributes
diff --git a/spec/fabricators/err_fabricator.rb b/spec/fabricators/err_fabricator.rb
index 2b92461..f22ce5e 100644
--- a/spec/fabricators/err_fabricator.rb
+++ b/spec/fabricators/err_fabricator.rb
@@ -9,19 +9,19 @@ end
 Fabricator :notice do
   err!
   message             'FooError: Too Much Bar'
-  backtrace           { random_backtrace }
+  backtrace!
   server_environment  { {'environment-name' => 'production'} }
   request             {{ 'component' => 'foo', 'action' => 'bar' }}
   notifier            {{ 'name' => 'Notifier', 'version' => '1', 'url' => 'http://toad.com' }}
 end
 
-def random_backtrace
-  backtrace = []
-  99.times {|t| backtrace << {
-    'number'  => rand(999),
-    'file'    => "/path/to/file/#{SecureRandom.hex(4)}.rb",
-    'method'  => ActiveSupport.methods.shuffle.first
-  }}
-  backtrace
+Fabricator :backtrace do
+  fingerprint "fingerprint"
+  lines(:count => 99) { Fabricate.build(:backtrace_line) }
 end
 
+Fabricator :backtrace_line do
+  number { rand(999) }
+  file { "/path/to/file/#{SecureRandom.hex(4)}.rb" }
+  method(:method) { ActiveSupport.methods.shuffle.first }
+end
diff --git a/spec/models/app_spec.rb b/spec/models/app_spec.rb
index c13cde1..e55f037 100644
--- a/spec/models/app_spec.rb
+++ b/spec/models/app_spec.rb
@@ -200,8 +200,8 @@ describe App do
 
     it 'captures the backtrace' do
       @notice = App.report_error!(@xml)
-      @notice.backtrace.size.should == 73
-      @notice.backtrace.last['file'].should == '[GEM_ROOT]/bin/rake'
+      @notice.backtrace_lines.size.should == 73
+      @notice.backtrace_lines.last['file'].should == '[GEM_ROOT]/bin/rake'
     end
 
     it 'captures the server_environment' do
@@ -228,7 +228,7 @@ describe App do
     it "should handle params with only a single line of backtrace" do
       xml = Rails.root.join('spec','fixtures','hoptoad_test_notice_with_one_line_of_backtrace.xml').read
       lambda { @notice = App.report_error!(xml) }.should_not raise_error
-      @notice.backtrace.length.should == 1
+      @notice.backtrace_lines.length.should == 1
     end
 
     it 'captures the current_user' do
@@ -238,7 +238,7 @@ describe App do
       @notice.current_user['email'].should == 'mr.bean@example.com'
       @notice.current_user['username'].should == 'mrbean'
     end
- 
+
   end
 
 
diff --git a/spec/models/backtrace_line_normalizer_spec.rb b/spec/models/backtrace_line_normalizer_spec.rb
new file mode 100644
index 0000000..bc2b77d
--- /dev/null
+++ b/spec/models/backtrace_line_normalizer_spec.rb
@@ -0,0 +1,14 @@
+require 'spec_helper'
+
+describe BacktraceLineNormalizer do
+  subject { described_class.new(raw_line).call }
+
+  describe "sanitize file" do
+    let(:raw_line) { { 'number' => rand(999), 'file' => nil, 'method' => ActiveSupport.methods.shuffle.first.to_s } }
+
+    it "should replace nil file with [unknown source]" do
+      subject['file'].should == "[unknown source]"
+    end
+
+  end
+end
diff --git a/spec/models/backtrace_spec.rb b/spec/models/backtrace_spec.rb
new file mode 100644
index 0000000..c240886
--- /dev/null
+++ b/spec/models/backtrace_spec.rb
@@ -0,0 +1,46 @@
+require 'spec_helper'
+
+describe Backtrace do
+  subject { described_class.new }
+
+  its(:fingerprint) { should be_present }
+
+  describe "#similar" do
+    context "no similar backtrace" do
+      its(:similar) { should be_nil }
+    end
+
+    context "similar backtrace exist" do
+      let!(:similar_backtrace) { Fabricate(:backtrace, :fingerprint => fingerprint) }
+      let(:fingerprint) { "fingerprint" }
+
+      before { subject.stub(:fingerprint => fingerprint) }
+
+      its(:similar) { should == similar_backtrace }
+    end
+  end
+
+  describe "find_or_create" do
+    subject { described_class.find_or_create(attributes) }
+    let(:attributes) { mock :attributes }
+    let(:backtrace) { mock :backtrace }
+
+    before { described_class.stub(:new => backtrace) }
+
+    context "no similar backtrace" do
+      before { backtrace.stub(:similar => nil) }
+      it "create new backtrace" do
+        described_class.should_receive(:create).with(attributes)
+
+        described_class.find_or_create(attributes)
+      end
+    end
+
+    context "similar backtrace exist" do
+      let(:similar_backtrace) { mock :similar_backtrace }
+      before { backtrace.stub(:similar => similar_backtrace) }
+
+      it { should == similar_backtrace }
+    end
+  end
+end
diff --git a/spec/models/notice_observer_spec.rb b/spec/models/notice_observer_spec.rb
index dca73fe..e7f3b49 100644
--- a/spec/models/notice_observer_spec.rb
+++ b/spec/models/notice_observer_spec.rb
@@ -46,6 +46,7 @@ describe NoticeObserver do
   describe "should send a notification if a notification service is configured" do
     let(:app) { Fabricate(:app, :email_at_notices => [1], :notification_service => Fabricate(:campfire_notification_service))}
     let(:err) { Fabricate(:err, :problem => Fabricate(:problem, :app => app, :notices_count => 100)) }
+    let(:backtrace) { Fabricate(:backtrace) }
 
     before do
       Errbit::Config.per_app_email_at_notices = true
@@ -59,13 +60,14 @@ describe NoticeObserver do
       app.notification_service.should_receive(:create_notification)
 
       Notice.create!(:err => err, :message => 'FooError: Too Much Bar', :server_environment => {'environment-name' => 'production'},
-                     :backtrace => [{ :error => 'Le Broken' }], :notifier => { 'name' => 'Notifier', 'version' => '1', 'url' => 'http://toad.com' })
+                     :backtrace => backtrace, :notifier => { 'name' => 'Notifier', 'version' => '1', 'url' => 'http://toad.com' })
     end
   end
 
   describe "should not send a notification if a notification service is not configured" do
     let(:app) { Fabricate(:app, :email_at_notices => [1], :notification_service => Fabricate(:notification_service))}
     let(:err) { Fabricate(:err, :problem => Fabricate(:problem, :app => app, :notices_count => 100)) }
+    let(:backtrace) { Fabricate(:backtrace) }
 
     before do
       Errbit::Config.per_app_email_at_notices = true
@@ -79,7 +81,7 @@ describe NoticeObserver do
       app.notification_service.should_not_receive(:create_notification)
 
       Notice.create!(:err => err, :message => 'FooError: Too Much Bar', :server_environment => {'environment-name' => 'production'},
-                     :backtrace => [{ :error => 'Le Broken' }], :notifier => { 'name' => 'Notifier', 'version' => '1', 'url' => 'http://toad.com' })
+                     :backtrace => backtrace, :notifier => { 'name' => 'Notifier', 'version' => '1', 'url' => 'http://toad.com' })
     end
   end
 
diff --git a/spec/views/notices/_backtrace.html.haml_spec.rb b/spec/views/notices/_backtrace.html.haml_spec.rb
deleted file mode 100644
index 07dca60..0000000
--- a/spec/views/notices/_backtrace.html.haml_spec.rb
+++ /dev/null
@@ -1,18 +0,0 @@
-require 'spec_helper'
-
-describe "notices/_backtrace.html.haml" do
-  describe 'missing file in backtrace' do
-    let(:notice) do
-      backtrace = { 'number' => rand(999), 'file' => nil, 'method' => ActiveSupport.methods.shuffle.first }
-      Fabricate(:notice, :backtrace => [backtrace])
-    end
-
-    it "should replace nil file with [unknown source]" do
-      assign :app, notice.err.app
-
-      render "notices/backtrace", :lines => notice.backtrace
-      rendered.should match(/\[unknown source\]/)
-    end
-  end
-end
-
--
libgit2 0.21.2