diff --git a/app/controllers/api/v1/markers_controller.rb b/app/controllers/api/v1/markers_controller.rb
index 8eaf7767df8..dac77fa14ff 100644
--- a/app/controllers/api/v1/markers_controller.rb
+++ b/app/controllers/api/v1/markers_controller.rb
@@ -8,37 +8,39 @@ class Api::V1::MarkersController < Api::BaseController
 
   def index
     with_read_replica do
-      @markers = current_user.markers.where(timeline: Array(params[:timeline])).index_by(&:timeline)
+      @markers = current_user_markers
     end
-
-    render json: serialize_map(@markers)
+    render json: marker_timeline_presenter, serializer: REST::MarkerTimelineSerializer
   end
 
   def create
-    Marker.transaction do
-      @markers = {}
-
-      resource_params.each_pair do |timeline, timeline_params|
-        @markers[timeline] = current_user.markers.find_or_create_by(timeline: timeline)
-        @markers[timeline].update!(timeline_params)
-      end
-    end
-
-    render json: serialize_map(@markers)
+    @markers = create_markers_from_params
+    render json: marker_timeline_presenter, serializer: REST::MarkerTimelineSerializer
   rescue ActiveRecord::StaleObjectError
     render json: { error: 'Conflict during update, please try again' }, status: 409
   end
 
   private
 
-  def serialize_map(map)
-    serialized = {}
+  def marker_timeline_presenter
+    MarkerTimelinePresenter.new(@markers)
+  end
 
-    map.each_pair do |key, value|
-      serialized[key] = ActiveModelSerializers::SerializableResource.new(value, serializer: REST::MarkerSerializer).as_json
+  def current_user_markers
+    current_user.markers.where(timeline: Array(params[:timeline]))
+  end
+
+  def create_markers_from_params
+    [].tap do |markers|
+      Marker.transaction do
+        resource_params.each_pair do |timeline, timeline_params|
+          current_user.markers.find_or_create_by(timeline: timeline).tap do |marker|
+            marker.update!(timeline_params)
+            markers << marker
+          end
+        end
+      end
     end
-
-    Oj.dump(serialized)
   end
 
   def resource_params
diff --git a/app/presenters/marker_timeline_presenter.rb b/app/presenters/marker_timeline_presenter.rb
new file mode 100644
index 00000000000..dd80f18c390
--- /dev/null
+++ b/app/presenters/marker_timeline_presenter.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+class MarkerTimelinePresenter
+  include ActiveModel::Model
+
+  alias read_attribute_for_serialization send
+
+  attr_reader :markers
+
+  def initialize(markers)
+    @markers = markers
+  end
+
+  Marker::TIMELINES.each do |timeline|
+    define_method timeline.to_sym do
+      markers.find { |marker| marker.timeline == timeline }
+    end
+  end
+
+  def timeline_present?(value)
+    markers.map(&:timeline).include?(value)
+  end
+end
diff --git a/app/serializers/rest/marker_timeline_serializer.rb b/app/serializers/rest/marker_timeline_serializer.rb
new file mode 100644
index 00000000000..14d221b2900
--- /dev/null
+++ b/app/serializers/rest/marker_timeline_serializer.rb
@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class REST::MarkerTimelineSerializer < ActiveModel::Serializer
+  Marker::TIMELINES.each do |timeline|
+    has_one timeline.to_sym,
+            if: -> { timeline_present?(timeline) },
+            serializer: REST::MarkerSerializer
+  end
+
+  delegate :timeline_present?, to: :object
+end