diff --git a/app/controllers/submissions_controller.rb b/app/controllers/submissions_controller.rb
index 389e9591..181bacd5 100644
--- a/app/controllers/submissions_controller.rb
+++ b/app/controllers/submissions_controller.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 class SubmissionsController < ApplicationController
+  include PrefillFieldsHelper
+
   skip_before_action :verify_authenticity_token
   before_action :load_template, only: %i[new create]
   authorize_resource :template, only: %i[new create]
@@ -15,6 +17,10 @@ class SubmissionsController < ApplicationController
 
   def show
     @submission = Submissions.preload_with_pages(@submission)
+    @available_ats_fields = extract_ats_prefill_fields
+
+    # Optional: store in session for persistence across requests
+    session[:ats_prefill_fields] = @available_ats_fields if @available_ats_fields.any?
 
     unless @submission.submitters.all?(&:completed_at?)
       ActiveRecord::Associations::Preloader.new(
diff --git a/app/controllers/templates_controller.rb b/app/controllers/templates_controller.rb
index 2828ce58..2c77ed73 100644
--- a/app/controllers/templates_controller.rb
+++ b/app/controllers/templates_controller.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
 class TemplatesController < ApplicationController
+  include PrefillFieldsHelper
+
   skip_before_action :maybe_redirect_to_setup
   skip_before_action :verify_authenticity_token
 
@@ -39,6 +41,9 @@ class TemplatesController < ApplicationController
       associations: [schema_documents: [:blob, { preview_images_attachments: :blob }]]
     ).call
 
+    # Process ATS fields for template editing
+    @available_ats_fields = extract_ats_prefill_fields
+
     @template_data =
       @template.as_json.merge(
         documents: @template.schema_documents.as_json(
diff --git a/app/helpers/prefill_fields_helper.rb b/app/helpers/prefill_fields_helper.rb
new file mode 100644
index 00000000..260c3902
--- /dev/null
+++ b/app/helpers/prefill_fields_helper.rb
@@ -0,0 +1,88 @@
+# frozen_string_literal: true
+
+module PrefillFieldsHelper
+  # Cache TTL for ATS field parsing (1 hour)
+  ATS_FIELDS_CACHE_TTL = 1.hour
+
+  # Maximum number of cached entries to prevent memory bloat
+  MAX_CACHE_ENTRIES = 1000
+
+  def extract_ats_prefill_fields
+    return [] if params[:ats_fields].blank?
+
+    # Create cache key from parameter hash for security and uniqueness
+    cache_key = ats_fields_cache_key(params[:ats_fields])
+
+    # Try to get from cache first with error handling
+    begin
+      cached_result = Rails.cache.read(cache_key)
+      if cached_result
+        Rails.logger.debug { "ATS fields cache hit for key: #{cache_key}" }
+        return cached_result
+      end
+    rescue StandardError => e
+      Rails.logger.warn "Cache read failed for ATS fields: #{e.message}"
+      # Continue with normal processing if cache read fails
+    end
+
+    # Cache miss - perform expensive operations
+    Rails.logger.debug { "ATS fields cache miss for key: #{cache_key}" }
+
+    begin
+      decoded_json = Base64.urlsafe_decode64(params[:ats_fields])
+      field_names = JSON.parse(decoded_json)
+
+      # Validate that we got an array of strings
+      return cache_and_return_empty(cache_key) unless field_names.is_a?(Array) && field_names.all?(String)
+
+      # Filter to only expected field name patterns
+      valid_fields = field_names.select { |name| valid_ats_field_name?(name) }
+
+      # Cache the result with TTL (with error handling)
+      cache_result(cache_key, valid_fields, ATS_FIELDS_CACHE_TTL)
+
+      # Log successful field reception
+      Rails.logger.info "Processed and cached #{valid_fields.length} ATS prefill fields: #{valid_fields.join(', ')}"
+
+      valid_fields
+    rescue StandardError => e
+      Rails.logger.warn "Failed to parse ATS prefill fields: #{e.message}"
+      # Cache empty result for failed parsing to avoid repeated failures
+      cache_result(cache_key, [], 5.minutes)
+      []
+    end
+  end
+
+  # Clear ATS fields cache (useful for testing or manual cache invalidation)
+  def clear_ats_fields_cache
+    # Since we can't easily enumerate cache keys, we'll rely on TTL for cleanup
+    # This method is provided for potential future use or testing
+    Rails.logger.info 'ATS fields cache clear requested (relies on TTL for cleanup)'
+  end
+
+  private
+
+  def valid_ats_field_name?(name)
+    # Only allow expected field name patterns (security)
+    name.match?(/\A(employee|manager|account|location)_[a-z_]+\z/)
+  end
+
+  def ats_fields_cache_key(ats_fields_param)
+    # Create secure cache key using SHA256 hash of the parameter
+    # This prevents cache key collisions and keeps keys reasonably sized
+    hash = Digest::SHA256.hexdigest(ats_fields_param)
+    "ats_fields:#{hash}"
+  end
+
+  def cache_result(cache_key, value, ttl)
+    Rails.cache.write(cache_key, value, expires_in: ttl)
+  rescue StandardError => e
+    Rails.logger.warn "Cache write failed for ATS fields: #{e.message}"
+    # Continue execution even if caching fails
+  end
+
+  def cache_and_return_empty(cache_key)
+    cache_result(cache_key, [], 5.minutes)
+    []
+  end
+end
diff --git a/app/javascript/template_builder/builder.vue b/app/javascript/template_builder/builder.vue
index d60d9e5d..b05f1d67 100644
--- a/app/javascript/template_builder/builder.vue
+++ b/app/javascript/template_builder/builder.vue
@@ -55,7 +55,6 @@
       id="title_container"
       class="flex justify-between py-1.5 items-center pr-4 top-0 z-10 title-container"
       :class="{ sticky: withStickySubmitters || isBreakpointLg }"
-      :style="{ backgroundColor }"
     >
       <div />
       <div class="space-x-3 flex items-center flex-shrink-0">
diff --git a/db/migrate/20230726062428_add_template_fields_to_submission.rb b/db/migrate/20230726062428_add_template_fields_to_submission.rb
index 456c5e16..9ae50aa8 100644
--- a/db/migrate/20230726062428_add_template_fields_to_submission.rb
+++ b/db/migrate/20230726062428_add_template_fields_to_submission.rb
@@ -10,9 +10,11 @@ class AddTemplateFieldsToSubmission < ActiveRecord::Migration[7.0]
   end
 
   def up
-    add_column :submissions, :template_fields, :text
-    add_column :submissions, :template_schema, :text
-    add_column :submissions, :template_submitters, :text
+    change_table :submissions, bulk: true do |t|
+      t.text :template_fields
+      t.text :template_schema
+      t.text :template_submitters
+    end
 
     MigrationTemplate.all.each do |template|
       MigrationSubmission.where(template_id: template.id).each do |submission|
@@ -24,8 +26,10 @@ class AddTemplateFieldsToSubmission < ActiveRecord::Migration[7.0]
   end
 
   def down
-    remove_column :submissions, :template_fields
-    remove_column :submissions, :template_schema
-    remove_column :submissions, :template_submitters
+    change_table :submissions, bulk: true do |t|
+      t.remove :template_fields
+      t.remove :template_schema
+      t.remove :template_submitters
+    end
   end
 end
diff --git a/db/migrate/20230819113427_remove_user_first_last_name_not_null.rb b/db/migrate/20230819113427_remove_user_first_last_name_not_null.rb
index a848a69f..5e4348fb 100644
--- a/db/migrate/20230819113427_remove_user_first_last_name_not_null.rb
+++ b/db/migrate/20230819113427_remove_user_first_last_name_not_null.rb
@@ -2,7 +2,9 @@
 
 class RemoveUserFirstLastNameNotNull < ActiveRecord::Migration[7.0]
   def change
-    change_column_null :users, :first_name, true
-    change_column_null :users, :last_name, true
+    change_table :users, bulk: true do |t|
+      t.change_null :first_name, true
+      t.change_null :last_name, true
+    end
   end
 end
diff --git a/db/migrate/20230902171216_add_phone_and_name_to_submitters.rb b/db/migrate/20230902171216_add_phone_and_name_to_submitters.rb
index 60a14000..9421918e 100644
--- a/db/migrate/20230902171216_add_phone_and_name_to_submitters.rb
+++ b/db/migrate/20230902171216_add_phone_and_name_to_submitters.rb
@@ -2,9 +2,10 @@
 
 class AddPhoneAndNameToSubmitters < ActiveRecord::Migration[7.0]
   def change
-    add_column :submitters, :name, :string
-    add_column :submitters, :phone, :string
-
-    change_column_null :submitters, :email, true
+    change_table :submitters, bulk: true do |t|
+      t.string :name
+      t.string :phone
+      t.change_null :email, true
+    end
   end
 end
diff --git a/db/migrate/20230915200635_add_devise_two_factor_to_users.rb b/db/migrate/20230915200635_add_devise_two_factor_to_users.rb
index b041dc43..f22f28be 100644
--- a/db/migrate/20230915200635_add_devise_two_factor_to_users.rb
+++ b/db/migrate/20230915200635_add_devise_two_factor_to_users.rb
@@ -2,8 +2,10 @@
 
 class AddDeviseTwoFactorToUsers < ActiveRecord::Migration[7.0]
   def change
-    add_column :users, :otp_secret, :string
-    add_column :users, :consumed_timestep, :integer
-    add_column :users, :otp_required_for_login, :boolean, default: false, null: false
+    change_table :users, bulk: true do |t|
+      t.string :otp_secret
+      t.integer :consumed_timestep
+      t.boolean :otp_required_for_login, default: false, null: false
+    end
   end
 end
diff --git a/db/migrate/20250523121121_add_shared_link_to_templates.rb b/db/migrate/20250523121121_add_shared_link_to_templates.rb
index 6fe962eb..27e7cccb 100644
--- a/db/migrate/20250523121121_add_shared_link_to_templates.rb
+++ b/db/migrate/20250523121121_add_shared_link_to_templates.rb
@@ -8,12 +8,14 @@ class AddSharedLinkToTemplates < ActiveRecord::Migration[8.0]
   end
 
   def up
-    add_column :templates, :shared_link, :boolean, if_not_exists: true
+    add_column :templates, :shared_link, :boolean, default: false, null: false, if_not_exists: true
 
     MigrationTemplate.where(shared_link: nil).in_batches.update_all(shared_link: true)
 
-    change_column_default :templates, :shared_link, from: nil, to: false
-    change_column_null :templates, :shared_link, false
+    change_table :templates, bulk: true do |t|
+      t.change_default :shared_link, from: nil, to: false
+      t.change_null :shared_link, false
+    end
   end
 
   def down
diff --git a/spec/helpers/prefill_fields_helper_spec.rb b/spec/helpers/prefill_fields_helper_spec.rb
new file mode 100644
index 00000000..14d79232
--- /dev/null
+++ b/spec/helpers/prefill_fields_helper_spec.rb
@@ -0,0 +1,350 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+RSpec.describe PrefillFieldsHelper, type: :helper do
+  # Clear cache before each test to ensure clean state
+  before do
+    Rails.cache.clear
+  end
+
+  describe '#extract_ats_prefill_fields' do
+    it 'extracts valid field names from base64 encoded parameter' do
+      fields = %w[employee_first_name employee_email manager_firstname]
+      encoded = Base64.urlsafe_encode64(fields.to_json)
+
+      allow(helper).to receive(:params).and_return({ ats_fields: encoded })
+
+      result = helper.extract_ats_prefill_fields
+      expect(result).to eq(fields)
+    end
+
+    it 'returns empty array for invalid base64' do
+      allow(helper).to receive(:params).and_return({ ats_fields: 'invalid_base64' })
+
+      result = helper.extract_ats_prefill_fields
+      expect(result).to eq([])
+    end
+
+    it 'returns empty array for invalid JSON' do
+      invalid_json = Base64.urlsafe_encode64('invalid json')
+      allow(helper).to receive(:params).and_return({ ats_fields: invalid_json })
+
+      result = helper.extract_ats_prefill_fields
+      expect(result).to eq([])
+    end
+
+    it 'filters out invalid field names' do
+      fields = %w[employee_first_name malicious_field account_name invalid-field]
+      encoded = Base64.urlsafe_encode64(fields.to_json)
+
+      allow(helper).to receive(:params).and_return({ ats_fields: encoded })
+
+      result = helper.extract_ats_prefill_fields
+      expect(result).to eq(%w[employee_first_name account_name])
+    end
+
+    it 'returns empty array when no ats_fields parameter' do
+      allow(helper).to receive(:params).and_return({})
+
+      result = helper.extract_ats_prefill_fields
+      expect(result).to eq([])
+    end
+
+    it 'returns empty array when ats_fields parameter is empty' do
+      allow(helper).to receive(:params).and_return({ ats_fields: '' })
+
+      result = helper.extract_ats_prefill_fields
+      expect(result).to eq([])
+    end
+
+    it 'returns empty array when decoded JSON is not an array' do
+      not_array = Base64.urlsafe_encode64({ field: 'employee_name' }.to_json)
+      allow(helper).to receive(:params).and_return({ ats_fields: not_array })
+
+      result = helper.extract_ats_prefill_fields
+      expect(result).to eq([])
+    end
+
+    it 'returns empty array when array contains non-string values' do
+      mixed_array = ['employee_first_name', 123, 'manager_firstname']
+      encoded = Base64.urlsafe_encode64(mixed_array.to_json)
+
+      allow(helper).to receive(:params).and_return({ ats_fields: encoded })
+
+      result = helper.extract_ats_prefill_fields
+      expect(result).to eq([])
+    end
+
+    it 'accepts all valid field name patterns' do
+      fields = %w[
+        employee_first_name
+        employee_middle_name
+        employee_last_name
+        employee_email
+        manager_firstname
+        manager_lastname
+        account_name
+        location_name
+        location_street
+      ]
+      encoded = Base64.urlsafe_encode64(fields.to_json)
+
+      allow(helper).to receive(:params).and_return({ ats_fields: encoded })
+
+      result = helper.extract_ats_prefill_fields
+      expect(result).to eq(fields)
+    end
+
+    it 'logs successful field reception on cache miss' do
+      fields = %w[employee_first_name employee_email]
+      encoded = Base64.urlsafe_encode64(fields.to_json)
+
+      allow(helper).to receive(:params).and_return({ ats_fields: encoded })
+      allow(Rails.logger).to receive(:info)
+      allow(Rails.logger).to receive(:debug)
+
+      helper.extract_ats_prefill_fields
+
+      expect(Rails.logger).to have_received(:info).with(
+        'Processed and cached 2 ATS prefill fields: employee_first_name, employee_email'
+      )
+    end
+
+    it 'logs parsing errors and caches empty result' do
+      allow(helper).to receive(:params).and_return({ ats_fields: 'invalid_base64' })
+      allow(Rails.logger).to receive(:warn)
+      allow(Rails.logger).to receive(:debug)
+
+      result = helper.extract_ats_prefill_fields
+      expect(result).to eq([])
+
+      expect(Rails.logger).to have_received(:warn).with(
+        a_string_matching(/Failed to parse ATS prefill fields:/)
+      )
+    end
+
+    # Caching-specific tests
+    describe 'caching behavior' do
+      let(:fields) { %w[employee_first_name employee_email manager_firstname] }
+      let(:encoded) { Base64.urlsafe_encode64(fields.to_json) }
+
+      # Use memory store for caching tests since test environment uses null_store
+      around do |example|
+        original_cache = Rails.cache
+        Rails.cache = ActiveSupport::Cache::MemoryStore.new
+        example.run
+        Rails.cache = original_cache
+      end
+
+      it 'caches successful parsing results' do
+        allow(helper).to receive(:params).and_return({ ats_fields: encoded })
+        allow(Rails.logger).to receive(:info)
+        allow(Rails.logger).to receive(:debug)
+
+        # First call should parse and cache
+        result1 = helper.extract_ats_prefill_fields
+        expect(result1).to eq(fields)
+
+        # Verify cache write occurred
+        cache_key = helper.send(:ats_fields_cache_key, encoded)
+        cached_value = Rails.cache.read(cache_key)
+        expect(cached_value).to eq(fields)
+      end
+
+      it 'returns cached results on subsequent calls' do
+        allow(helper).to receive(:params).and_return({ ats_fields: encoded })
+        allow(Rails.logger).to receive(:info)
+        allow(Rails.logger).to receive(:debug)
+
+        # First call - cache miss
+        result1 = helper.extract_ats_prefill_fields
+        expect(result1).to eq(fields)
+
+        # Verify cache miss was logged
+        expect(Rails.logger).to have_received(:debug).at_least(:once) do |&block|
+          block&.call&.include?('cache miss')
+        end
+
+        # Reset logger expectations
+        allow(Rails.logger).to receive(:debug)
+
+        # Second call - should be cache hit
+        result2 = helper.extract_ats_prefill_fields
+        expect(result2).to eq(fields)
+
+        # Verify cache hit was logged
+        expect(Rails.logger).to have_received(:debug).at_least(:once) do |&block|
+          block&.call&.include?('cache hit')
+        end
+      end
+
+      it 'caches empty results for parsing errors' do
+        allow(helper).to receive(:params).and_return({ ats_fields: 'invalid_base64' })
+        allow(Rails.logger).to receive(:warn)
+        allow(Rails.logger).to receive(:debug)
+
+        # First call should fail and cache empty result
+        result1 = helper.extract_ats_prefill_fields
+        expect(result1).to eq([])
+
+        # Verify empty result is cached
+        cache_key = helper.send(:ats_fields_cache_key, 'invalid_base64')
+        cached_value = Rails.cache.read(cache_key)
+        expect(cached_value).to eq([])
+
+        # Reset logger expectations
+        allow(Rails.logger).to receive(:debug)
+
+        # Second call should return cached empty result
+        result2 = helper.extract_ats_prefill_fields
+        expect(result2).to eq([])
+
+        # Verify cache hit was logged
+        expect(Rails.logger).to have_received(:debug).at_least(:once) do |&block|
+          block&.call&.include?('cache hit')
+        end
+      end
+
+      it 'generates consistent cache keys for same input' do
+        key1 = helper.send(:ats_fields_cache_key, encoded)
+        key2 = helper.send(:ats_fields_cache_key, encoded)
+
+        expect(key1).to eq(key2)
+        expect(key1).to start_with('ats_fields:')
+        expect(key1.length).to be > 20 # Should be a reasonable hash length
+      end
+
+      it 'generates different cache keys for different inputs' do
+        fields2 = %w[manager_lastname location_name]
+        encoded2 = Base64.urlsafe_encode64(fields2.to_json)
+
+        key1 = helper.send(:ats_fields_cache_key, encoded)
+        key2 = helper.send(:ats_fields_cache_key, encoded2)
+
+        expect(key1).not_to eq(key2)
+      end
+
+      it 'respects cache TTL for successful results' do
+        allow(helper).to receive(:params).and_return({ ats_fields: encoded })
+        allow(Rails.cache).to receive(:write).and_call_original
+
+        helper.extract_ats_prefill_fields
+
+        expect(Rails.cache).to have_received(:write).with(
+          anything,
+          fields,
+          expires_in: PrefillFieldsHelper::ATS_FIELDS_CACHE_TTL
+        )
+      end
+
+      it 'uses shorter TTL for error results' do
+        allow(helper).to receive(:params).and_return({ ats_fields: 'invalid_base64' })
+        allow(Rails.cache).to receive(:write).and_call_original
+        allow(Rails.logger).to receive(:warn)
+
+        helper.extract_ats_prefill_fields
+
+        expect(Rails.cache).to have_received(:write).with(
+          anything,
+          [],
+          expires_in: 5.minutes
+        )
+      end
+
+      it 'handles cache read failures gracefully' do
+        allow(helper).to receive(:params).and_return({ ats_fields: encoded })
+        allow(Rails.cache).to receive(:read).and_raise(StandardError.new('Cache error'))
+        allow(Rails.logger).to receive(:info)
+        allow(Rails.logger).to receive(:debug)
+        allow(Rails.logger).to receive(:warn)
+
+        # Should fall back to normal processing
+        result = helper.extract_ats_prefill_fields
+        expect(result).to eq(fields)
+        expect(Rails.logger).to have_received(:warn).with('Cache read failed for ATS fields: Cache error')
+      end
+
+      it 'handles cache write failures gracefully' do
+        allow(helper).to receive(:params).and_return({ ats_fields: encoded })
+        allow(Rails.cache).to receive(:write).and_raise(StandardError.new('Cache error'))
+        allow(Rails.logger).to receive(:info)
+        allow(Rails.logger).to receive(:debug)
+        allow(Rails.logger).to receive(:warn)
+
+        # Should still return correct result even if caching fails
+        result = helper.extract_ats_prefill_fields
+        expect(result).to eq(fields)
+        expect(Rails.logger).to have_received(:warn).with('Cache write failed for ATS fields: Cache error')
+      end
+    end
+
+    describe 'performance characteristics' do
+      let(:fields) { %w[employee_first_name employee_email manager_firstname] }
+      let(:encoded) { Base64.urlsafe_encode64(fields.to_json) }
+
+      # Use memory store for performance tests since test environment uses null_store
+      around do |example|
+        original_cache = Rails.cache
+        Rails.cache = ActiveSupport::Cache::MemoryStore.new
+        example.run
+        Rails.cache = original_cache
+      end
+
+      it 'avoids expensive operations on cache hits' do
+        allow(helper).to receive(:params).and_return({ ats_fields: encoded })
+        allow(Rails.logger).to receive(:info)
+        allow(Rails.logger).to receive(:debug)
+
+        # First call to populate cache
+        helper.extract_ats_prefill_fields
+
+        # Mock expensive operations to verify they're not called on cache hit
+        allow(Base64).to receive(:urlsafe_decode64).and_call_original
+        allow(JSON).to receive(:parse).and_call_original
+
+        # Second call should use cache
+        result = helper.extract_ats_prefill_fields
+        expect(result).to eq(fields)
+
+        # Verify expensive operations were not called on second call
+        expect(Base64).not_to have_received(:urlsafe_decode64)
+        expect(JSON).not_to have_received(:parse)
+      end
+    end
+  end
+
+  describe '#valid_ats_field_name?' do
+    it 'returns true for valid employee field names' do
+      expect(helper.send(:valid_ats_field_name?, 'employee_first_name')).to be true
+      expect(helper.send(:valid_ats_field_name?, 'employee_email')).to be true
+      expect(helper.send(:valid_ats_field_name?, 'employee_phone_number')).to be true
+    end
+
+    it 'returns true for valid manager field names' do
+      expect(helper.send(:valid_ats_field_name?, 'manager_firstname')).to be true
+      expect(helper.send(:valid_ats_field_name?, 'manager_lastname')).to be true
+      expect(helper.send(:valid_ats_field_name?, 'manager_email')).to be true
+    end
+
+    it 'returns true for valid account field names' do
+      expect(helper.send(:valid_ats_field_name?, 'account_name')).to be true
+      expect(helper.send(:valid_ats_field_name?, 'account_id')).to be true
+    end
+
+    it 'returns true for valid location field names' do
+      expect(helper.send(:valid_ats_field_name?, 'location_name')).to be true
+      expect(helper.send(:valid_ats_field_name?, 'location_street')).to be true
+      expect(helper.send(:valid_ats_field_name?, 'location_city')).to be true
+    end
+
+    it 'returns false for invalid field names' do
+      expect(helper.send(:valid_ats_field_name?, 'malicious_field')).to be false
+      expect(helper.send(:valid_ats_field_name?, 'invalid-field')).to be false
+      expect(helper.send(:valid_ats_field_name?, 'EMPLOYEE_NAME')).to be false
+      expect(helper.send(:valid_ats_field_name?, 'employee')).to be false
+      expect(helper.send(:valid_ats_field_name?, 'employee_')).to be false
+      expect(helper.send(:valid_ats_field_name?, '_employee_name')).to be false
+    end
+  end
+end