diff --git a/backend/src/modules/matrix.service.ts b/backend/src/modules/matrix.service.ts
index 0d870ec..eb2f332 100644
--- a/backend/src/modules/matrix.service.ts
+++ b/backend/src/modules/matrix.service.ts
@@ -29,6 +29,15 @@ type MatrixJoinedMembersResponse = {
     }>
 }
 
+type MatrixUserSession = {
+    accessToken: string
+    matrixUserId: string
+    validUntilMs: number
+}
+
+const matrixUserSessionCache = new Map<string, MatrixUserSession>()
+const matrixJoinedRoomCache = new Map<string, number>()
+
 const trimTrailingSlash = (value: string) => value.replace(/\/+$/, "")
 const readLocalDevRegistrationSharedSecret = () => {
     if (process.env.NODE_ENV === "production") return ""
@@ -296,11 +305,18 @@ export function matrixService(server: FastifyInstance) {
     }
 
     const createAccessTokenForUser = async (userId: string, tenantId: number | null) => {
+        const matrixUserId = await matrixUserIdForUser(userId, tenantId)
+        const cacheKey = `${tenantId || "global"}:${userId}`
+        const cachedSession = matrixUserSessionCache.get(cacheKey)
+
+        if (cachedSession && cachedSession.validUntilMs > Date.now() + 60_000) {
+            return cachedSession
+        }
+
         await provisionCurrentUser(userId, tenantId)
 
-        const matrixUserId = await matrixUserIdForUser(userId, tenantId)
         const serviceLogin = await ensureServiceAccessToken()
-        const validUntilMs = Date.now() + 10 * 60 * 1000
+        const validUntilMs = Date.now() + 30 * 60 * 1000
 
         const login = await requestMatrixJson<{ access_token: string }>(
             `/_synapse/admin/v1/users/${encodeURIComponent(matrixUserId)}/login`,
@@ -312,11 +328,14 @@ export function matrixService(server: FastifyInstance) {
             }
         )
 
-        return {
+        const session = {
             accessToken: login.access_token,
             matrixUserId,
             validUntilMs,
         }
+
+        matrixUserSessionCache.set(cacheKey, session)
+        return session
     }
 
     const getStatus = async () => {
@@ -655,6 +674,12 @@ export function matrixService(server: FastifyInstance) {
         room: { roomId: string, alias: string }
     ) => {
         const session = await createAccessTokenForUser(userId, tenantId)
+        const joinCacheKey = `${session.matrixUserId}:${room.roomId || room.alias}`
+        const joinedUntil = matrixJoinedRoomCache.get(joinCacheKey)
+
+        if (joinedUntil && joinedUntil > Date.now()) {
+            return session
+        }
 
         try {
             await requestMatrixJson(
@@ -672,6 +697,7 @@ export function matrixService(server: FastifyInstance) {
             }
         }
 
+        matrixJoinedRoomCache.set(joinCacheKey, Date.now() + 30 * 60 * 1000)
         return session
     }
 
diff --git a/frontend/pages/communication/index.vue b/frontend/pages/communication/index.vue
index 2fcfc05..1ac2306 100644
--- a/frontend/pages/communication/index.vue
+++ b/frontend/pages/communication/index.vue
@@ -24,6 +24,8 @@ const matrixMessageSending = ref(false)
 const matrixAutoRefreshActive = ref(false)
 const lastUpdated = ref(null)
 let matrixRefreshInterval = null
+let matrixMessagesRequestActive = false
+let matrixMembersRequestActive = false
 
 const statusItems = computed(() => [
   {
@@ -125,7 +127,7 @@ const loadMatrixInfo = async () => {
     lastUpdated.value = new Date()
 
     if (generalRoomRes?.exists && canUseMatrixChat.value) {
-      await loadGeneralChat({ silent: true })
+      await loadGeneralChat({ silent: true, includeMembers: true })
     }
   } catch (error) {
     toast.add({
@@ -225,7 +227,7 @@ const provisionGeneralRoom = async () => {
       color: "success"
     })
 
-    await loadGeneralChat()
+    await loadGeneralChat({ includeMembers: true })
   } catch (error) {
     toast.add({
       title: "Allgemeiner Chat konnte nicht erstellt werden",
@@ -238,6 +240,9 @@ const provisionGeneralRoom = async () => {
 
 const loadGeneralMessages = async ({ silent = false } = {}) => {
   if (!canUseMatrixChat.value) return
+  if (matrixMessagesRequestActive) return
+
+  matrixMessagesRequestActive = true
   if (!silent) matrixMessagesLoading.value = true
 
   try {
@@ -258,12 +263,16 @@ const loadGeneralMessages = async ({ silent = false } = {}) => {
       })
     }
   } finally {
+    matrixMessagesRequestActive = false
     if (!silent) matrixMessagesLoading.value = false
   }
 }
 
 const loadGeneralMembers = async ({ silent = false } = {}) => {
   if (!canUseMatrixChat.value) return
+  if (matrixMembersRequestActive) return
+
+  matrixMembersRequestActive = true
   if (!silent) matrixMembersLoading.value = true
 
   try {
@@ -277,15 +286,17 @@ const loadGeneralMembers = async ({ silent = false } = {}) => {
       })
     }
   } finally {
+    matrixMembersRequestActive = false
     if (!silent) matrixMembersLoading.value = false
   }
 }
 
-const loadGeneralChat = async ({ silent = false } = {}) => {
-  await Promise.all([
-    loadGeneralMessages({ silent }),
-    loadGeneralMembers({ silent })
-  ])
+const loadGeneralChat = async ({ silent = false, includeMembers = false } = {}) => {
+  await loadGeneralMessages({ silent })
+
+  if (includeMembers) {
+    await loadGeneralMembers({ silent })
+  }
 }
 
 const sendMatrixMessage = async () => {
@@ -321,7 +332,6 @@ const sendMatrixMessage = async () => {
     matrixMessages.value = matrixMessages.value.map((item) =>
       item.id === optimisticId ? message : item
     )
-    await loadGeneralMembers({ silent: true })
   } catch (error) {
     matrixMessages.value = matrixMessages.value.map((item) =>
       item.id === optimisticId ? { ...item, pending: false, failed: true } : item
@@ -343,7 +353,7 @@ const startMatrixAutoRefresh = () => {
     if (!document.hidden && canUseMatrixChat.value) {
       loadGeneralChat({ silent: true })
     }
-  }, 5000)
+  }, 15000)
 }
 
 const stopMatrixAutoRefresh = () => {