diff --git a/src/main/java/mops/gruppen2/infrastructure/GroupCache.java b/src/main/java/mops/gruppen2/infrastructure/GroupCache.java
new file mode 100644
index 0000000..8b29962
--- /dev/null
+++ b/src/main/java/mops/gruppen2/infrastructure/GroupCache.java
@@ -0,0 +1,57 @@
+package mops.gruppen2.infrastructure;
+
+import lombok.RequiredArgsConstructor;
+import mops.gruppen2.domain.model.group.Group;
+import mops.gruppen2.domain.service.ProjectionService;
+import org.springframework.boot.context.event.ApplicationReadyEvent;
+import org.springframework.context.annotation.Scope;
+import org.springframework.context.event.EventListener;
+import org.springframework.stereotype.Component;
+
+import java.util.List;
+import java.util.Map;
+import java.util.UUID;
+
+@RequiredArgsConstructor
+@Component
+@Scope("singleton")
+public class GroupCache {
+
+    private final ProjectionService projectionService;
+
+    private long version;
+    private boolean isValid;
+    private String principal;
+
+    private Map<UUID, Group> groups;
+
+    private List<UUID> userGroups;
+    private List<UUID> publics;
+    private List<UUID> privates;
+    private List<UUID> lectures;
+
+    @EventListener(ApplicationReadyEvent.class)
+    public void init() {
+        groups = projectionService.projectAllGroups();
+
+        Group current;
+        UUID currentId;
+        for (Map.Entry<UUID, Group> entry : groups.entrySet()) {
+            current = entry.getValue();
+            currentId = entry.getKey();
+
+            if (current.isMember(principal)) {
+                userGroups.add(currentId);
+            }
+            if (current.isPublic()) {
+                publics.add(currentId);
+            }
+            if (current.isPrivate()) {
+                privates.add(currentId);
+            }
+            if (current.isLecture()) {
+                lectures.add(currentId);
+            }
+        }
+    }
+}