diff --git a/client/src/components/dueDates/DueDateSingle.vue b/client/src/components/dueDates/DueDateSingle.vue
index 45148417..84fb2306 100644
--- a/client/src/components/dueDates/DueDateSingle.vue
+++ b/client/src/components/dueDates/DueDateSingle.vue
@@ -17,7 +17,7 @@ const assignmentType = t(props.dueDate.assignment_type_translation_key);
 
 const courseSessionsStore = useCourseSessionsStore();
 const courseSession = courseSessionsStore.allCourseSessions.find(
-  (cs: CourseSession) => cs.id === props.dueDate.course_session
+  (cs: CourseSession) => cs.id === props.dueDate.course_session_id
 );
 
 if (!courseSession) {
@@ -28,10 +28,10 @@ const isExpert = courseSessionsStore.hasCockpit(courseSession);
 const url = isExpert ? props.dueDate.url_expert : props.dueDate.url;
 
 const courseSessionTitle = computed(() => {
-  if (props.dueDate.course_session) {
+  if (props.dueDate.course_session_id) {
     return (
-      courseSessionsStore.getCourseSessionById(props.dueDate.course_session)?.title ??
-      ""
+      courseSessionsStore.getCourseSessionById(props.dueDate.course_session_id)
+        ?.title ?? ""
     );
   }
   return "";
diff --git a/client/src/components/header/MainNavigationBar.vue b/client/src/components/header/MainNavigationBar.vue
index 76a6a92d..375ca904 100644
--- a/client/src/components/header/MainNavigationBar.vue
+++ b/client/src/components/header/MainNavigationBar.vue
@@ -135,7 +135,7 @@ onMounted(() => {
                   <template v-if="courseSessionsStore.currentCourseSessionHasCockpit">
                     <router-link
                       data-cy="navigation-cockpit-link"
-                      :to="`${courseSessionsStore.currentCourseSession.course_url}/cockpit`"
+                      :to="`${courseSessionsStore.currentCourseSession.course.slug}/cockpit`"
                       class="nav-item"
                       :class="{ 'nav-item--active': inCockpit() }"
                     >
diff --git a/client/src/components/header/MobileMenu.vue b/client/src/components/header/MobileMenu.vue
index bc61f91b..c14d4735 100644
--- a/client/src/components/header/MobileMenu.vue
+++ b/client/src/components/header/MobileMenu.vue
@@ -64,7 +64,7 @@ const courseSessionsStore = useCourseSessionsStore();
                 <li class="mb-6">
                   <button
                     data-cy="navigation-mobile-cockpit-link"
-                    @click="clickLink(`${courseSession.course_url}/cockpit`)"
+                    @click="clickLink(`${courseSession.course.slug}/cockpit`)"
                   >
                     {{ $t("cockpit.title") }}
                   </button>
diff --git a/client/src/pages/AppointmentsPage.vue b/client/src/pages/AppointmentsPage.vue
index 1d26beb5..6d82d0ac 100644
--- a/client/src/pages/AppointmentsPage.vue
+++ b/client/src/pages/AppointmentsPage.vue
@@ -101,14 +101,14 @@ const appointments = computed(() => {
 
 const isMatchingSession = (dueDate: DueDate) =>
   selectedSession.value.id === UNFILTERED ||
-  dueDate.course_session === selectedSession.value.id;
+  dueDate.course_session_id === selectedSession.value.id;
 
 const isMatchingCircle = (dueDate: DueDate) =>
   selectedCircle.value.id === UNFILTERED ||
   dueDate.circle?.id === selectedCircle.value.id;
 
 const isMatchingCourse = (dueDate: DueDate) =>
-  courseSessions.value.map((cs) => cs.id).includes(dueDate.course_session);
+  courseSessions.value.map((cs) => cs.id).includes(dueDate.course_session_id);
 
 const numAppointmentsToShow = ref(7);
 const canLoadMore = computed(() => {
diff --git a/client/src/pages/DashboardPage.vue b/client/src/pages/DashboardPage.vue
index bd600e4e..9098f5e7 100644
--- a/client/src/pages/DashboardPage.vue
+++ b/client/src/pages/DashboardPage.vue
@@ -21,7 +21,7 @@ const allDueDates = courseSessionsStore.allDueDates();
 const getNextStepLink = (courseSession: CourseSession) => {
   return computed(() => {
     if (courseSessionsStore.hasCockpit(courseSession)) {
-      return `${courseSession.course_url}/cockpit`;
+      return `${courseSession.course.slug}/cockpit`;
     }
     return getLearningPathUrl(courseSession.course.slug);
   });
diff --git a/client/src/types.ts b/client/src/types.ts
index 921058a3..d8b92282 100644
--- a/client/src/types.ts
+++ b/client/src/types.ts
@@ -518,7 +518,6 @@ export interface CourseSession {
   title: string;
   start_date: string;
   end_date: string;
-  course_url: string;
   due_dates: DueDate[];
 }
 
@@ -672,5 +671,6 @@ export type DueDate = SimpleDueDate & {
   subtitle: string;
   url: string;
   url_expert: string;
+  course_session_id: string;
   circle: CircleLight | null;
 };
diff --git a/server/vbv_lernwelt/course/serializers.py b/server/vbv_lernwelt/course/serializers.py
index c647ab3a..e28ed024 100644
--- a/server/vbv_lernwelt/course/serializers.py
+++ b/server/vbv_lernwelt/course/serializers.py
@@ -53,20 +53,14 @@ class CourseSessionSerializer(serializers.ModelSerializer):
     id = StringIDField()
 
     course = serializers.SerializerMethodField()
-    course_url = serializers.SerializerMethodField()
+    # course_url = serializers.SerializerMethodField()
     due_dates = serializers.SerializerMethodField()
 
     def get_course(self, obj):
         return CourseSerializer(obj.course).data
 
-    def get_course_url(self, obj):
-        return obj.course.get_course_url()
-
-    def get_documents(self, obj):
-        documents = CircleDocument.objects.filter(
-            course_session=obj, file__upload_finished_at__isnull=False
-        )
-        return CircleDocumentSerializer(documents, many=True).data
+    # def get_course_url(self, obj):
+    #     return obj.course.get_course_url()
 
     def get_due_dates(self, obj):
         due_dates = DueDate.objects.filter(course_session=obj)
@@ -82,7 +76,6 @@ class CourseSessionSerializer(serializers.ModelSerializer):
             "title",
             "start_date",
             "end_date",
-            "course_url",
             "due_dates",
         ]
 
diff --git a/server/vbv_lernwelt/duedate/migrations/0006_duedate_circle_data.py b/server/vbv_lernwelt/duedate/migrations/0006_duedate_circle_data.py
new file mode 100644
index 00000000..bda99d6b
--- /dev/null
+++ b/server/vbv_lernwelt/duedate/migrations/0006_duedate_circle_data.py
@@ -0,0 +1,17 @@
+# Generated by Django 3.2.20 on 2023-10-10 13:05
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("duedate", "0005_auto_20230925_1648"),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name="duedate",
+            name="circle_data",
+            field=models.JSONField(blank=True, default=dict),
+        ),
+    ]
diff --git a/server/vbv_lernwelt/duedate/migrations/0007_auto_20231010_1505.py b/server/vbv_lernwelt/duedate/migrations/0007_auto_20231010_1505.py
new file mode 100644
index 00000000..201a1c44
--- /dev/null
+++ b/server/vbv_lernwelt/duedate/migrations/0007_auto_20231010_1505.py
@@ -0,0 +1,21 @@
+# Generated by Django 3.2.20 on 2023-10-10 13:05
+
+from django.db import migrations
+from django.db.migrations import RunPython
+
+
+def trigger_due_date_save(apps, schema_editor):
+    # need to load concrete model, so that wagtail page has `specific` instance  method...
+    from vbv_lernwelt.duedate.models import DueDate
+
+    for due_date in DueDate.objects.all():
+        # trigger save to prefetch circle data
+        due_date.save()
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("duedate", "0006_duedate_circle_data"),
+    ]
+
+    operations = [RunPython(trigger_due_date_save)]
diff --git a/server/vbv_lernwelt/duedate/models.py b/server/vbv_lernwelt/duedate/models.py
index a5ba2854..14e2f9d6 100644
--- a/server/vbv_lernwelt/duedate/models.py
+++ b/server/vbv_lernwelt/duedate/models.py
@@ -60,6 +60,7 @@ class DueDate(models.Model):
     )
 
     page = models.ForeignKey(Page, on_delete=models.SET_NULL, null=True, blank=True)
+    circle_data = models.JSONField(default=dict, blank=True)
 
     class Meta:
         ordering = ["start", "end"]
@@ -80,6 +81,21 @@ class DueDate(models.Model):
 
         return result
 
+    def save(self, *args, **kwargs):
+        try:
+            circle = self.get_circle()
+            # prefetch circle data, because loading it dynamically is too slow
+            if circle:
+                self.circle_data = {
+                    "id": str(circle.id),
+                    "title": circle.title,
+                    "slug": circle.slug,
+                }
+        except Exception:
+            # noop
+            pass
+        super().save(*args, **kwargs)
+
     @property
     def display_subtitle(self):
         result = ""
diff --git a/server/vbv_lernwelt/duedate/serializers.py b/server/vbv_lernwelt/duedate/serializers.py
index a7ab81f6..fe11dd74 100644
--- a/server/vbv_lernwelt/duedate/serializers.py
+++ b/server/vbv_lernwelt/duedate/serializers.py
@@ -6,11 +6,9 @@ from vbv_lernwelt.duedate.models import DueDate
 
 class DueDateSerializer(serializers.ModelSerializer):
     id = StringIDField()
+    course_session_id = serializers.SerializerMethodField()
     circle = serializers.SerializerMethodField()
 
-    # course_session = StringIDField()
-    # page = StringIDField()
-
     class Meta:
         model = DueDate
         fields = [
@@ -24,18 +22,18 @@ class DueDateSerializer(serializers.ModelSerializer):
             "subtitle",
             "url",
             "url_expert",
-            "course_session",
-            "page",
+            "course_session_id",
             "circle",
         ]
 
-    def get_circle(self, obj):
-        circle = obj.get_circle()
+    def get_course_session_id(self, obj):
+        return str(obj.course_session.id)
 
-        if circle:
+    def get_circle(self, obj):
+        if obj.circle_data:
             return {
-                "id": str(circle.id),
-                "title": circle.title,
-                "translation_key": circle.translation_key,
+                "id": obj.circle_data.get("id"),
+                "title": obj.circle_data.get("title"),
+                "slug": obj.circle_data.get("slug"),
             }
         return None
diff --git a/server/vbv_lernwelt/notify/migrations/0003_truncate_notifications.py b/server/vbv_lernwelt/notify/migrations/0003_truncate_notifications.py
index 8751eb88..4e289876 100644
--- a/server/vbv_lernwelt/notify/migrations/0003_truncate_notifications.py
+++ b/server/vbv_lernwelt/notify/migrations/0003_truncate_notifications.py
@@ -6,7 +6,10 @@ from django.db import migrations
 def init_user_notification_emails(apps=None, schema_editor=None):
     User = apps.get_model("core", "User")
     for u in User.objects.all():
-        u.additional_json_data["email_notification_categories"] = ["NOTIFICATION"]
+        u.additional_json_data["email_notification_categories"] = [
+            "INFORMATION",
+            "USER_INTERACTION",
+        ]
         u.save()