diff --git a/backend/src/modules/matrix.service.ts b/backend/src/modules/matrix.service.ts
index eb2f332..213f435 100644
--- a/backend/src/modules/matrix.service.ts
+++ b/backend/src/modules/matrix.service.ts
@@ -35,8 +35,18 @@ type MatrixUserSession = {
     validUntilMs: number
 }
 
+type MatrixCachedValue<T = any> = {
+    exists: true
+    cachedUntil: number
+    value: T
+}
+
 const matrixUserSessionCache = new Map<string, MatrixUserSession>()
 const matrixJoinedRoomCache = new Map<string, number>()
+const matrixProvisionedUserCache = new Map<string, number>()
+const matrixTenantSpaceCache = new Map<string, MatrixCachedValue>()
+const matrixTenantRoomCache = new Map<string, MatrixCachedValue>()
+let matrixServiceSessionCache: MatrixUserSession | null = null
 
 const trimTrailingSlash = (value: string) => value.replace(/\/+$/, "")
 const readLocalDevRegistrationSharedSecret = () => {
@@ -229,6 +239,10 @@ export function matrixService(server: FastifyInstance) {
             )
         }
 
+        if (matrixServiceSessionCache && matrixServiceSessionCache.validUntilMs > Date.now() + 60_000) {
+            return matrixServiceSessionCache
+        }
+
         const username = serviceUserLocalpart()
         const password = serviceUserPassword()
 
@@ -240,7 +254,14 @@ export function matrixService(server: FastifyInstance) {
             }
         }
 
-        return loginMatrixUser(username, password)
+        const login = await loginMatrixUser(username, password)
+        matrixServiceSessionCache = {
+            accessToken: login.access_token,
+            matrixUserId: login.user_id,
+            validUntilMs: Date.now() + 30 * 60 * 1000,
+        }
+
+        return matrixServiceSessionCache
     }
 
     const getCurrentUserDisplayName = async (userId: string, tenantId: number | null) => {
@@ -320,7 +341,7 @@ export function matrixService(server: FastifyInstance) {
 
         const login = await requestMatrixJson<{ access_token: string }>(
             `/_synapse/admin/v1/users/${encodeURIComponent(matrixUserId)}/login`,
-            serviceLogin.access_token,
+            serviceLogin.accessToken,
             {
                 method: "POST",
                 headers: { "Content-Type": "application/json" },
@@ -386,11 +407,25 @@ export function matrixService(server: FastifyInstance) {
 
         const username = await matrixLocalpartForUser(userId, tenantId)
         const matrixUserId = await matrixUserIdForUser(userId, tenantId)
-        const password = randomBytes(32).toString("base64url")
         const displayName = await getCurrentUserDisplayName(userId, tenantId)
+        const cacheKey = `${tenantId || "global"}:${userId}`
+        const cachedUntil = matrixProvisionedUserCache.get(cacheKey)
+
+        if (cachedUntil && cachedUntil > Date.now()) {
+            return {
+                matrixUserId,
+                localpart: username,
+                displayName,
+                created: false,
+                alreadyExisted: true,
+            }
+        }
+
+        const password = randomBytes(32).toString("base64url")
 
         try {
             await registerWithSharedSecret(username, password, false)
+            matrixProvisionedUserCache.set(cacheKey, Date.now() + 30 * 60 * 1000)
 
             return {
                 matrixUserId,
@@ -401,6 +436,8 @@ export function matrixService(server: FastifyInstance) {
             }
         } catch (err: any) {
             if (err.errcode === "M_USER_IN_USE") {
+                matrixProvisionedUserCache.set(cacheKey, Date.now() + 30 * 60 * 1000)
+
                 return {
                     matrixUserId,
                     localpart: username,
@@ -478,23 +515,37 @@ export function matrixService(server: FastifyInstance) {
 
     const provisionCurrentTenantSpace = async (userId: string, tenantId: number | null) => {
         const tenant = await getCurrentTenant(tenantId)
+        const cacheKey = String(tenant.id)
+        const cachedSpace = matrixTenantSpaceCache.get(cacheKey)
+
+        if (cachedSpace?.exists && cachedSpace.cachedUntil > Date.now()) {
+            return cachedSpace.value
+        }
+
         const existing = await getTenantSpaceStatus(tenant.id)
         const userAccount = await provisionCurrentUser(userId, tenant.id)
 
         if (existing.exists) {
-            return {
+            const value = {
                 ...existing,
                 created: false,
                 alreadyExisted: true,
                 invitedUserId: userAccount.matrixUserId,
             }
+
+            matrixTenantSpaceCache.set(cacheKey, {
+                exists: true,
+                cachedUntil: Date.now() + 30 * 60 * 1000,
+                value,
+            })
+            return value
         }
 
         const serviceLogin = await ensureServiceAccessToken()
         const aliasLocalpart = tenantSpaceAliasLocalpart(tenant)
         const createdRoom = await requestMatrixJson<{ room_id: string }>(
             "/_matrix/client/v3/createRoom",
-            serviceLogin.access_token,
+            serviceLogin.accessToken,
             {
                 method: "POST",
                 headers: { "Content-Type": "application/json" },
@@ -521,7 +572,7 @@ export function matrixService(server: FastifyInstance) {
             }
         )
 
-        return {
+        const value = {
             tenantId: tenant.id,
             tenantName: tenant.name,
             alias: tenantSpaceAlias(tenant),
@@ -530,8 +581,15 @@ export function matrixService(server: FastifyInstance) {
             alreadyExisted: false,
             roomId: createdRoom.room_id,
             invitedUserId: userAccount.matrixUserId,
-            serviceUserId: serviceLogin.user_id,
+            serviceUserId: serviceLogin.matrixUserId,
         }
+
+        matrixTenantSpaceCache.set(cacheKey, {
+            exists: true,
+            cachedUntil: Date.now() + 30 * 60 * 1000,
+            value,
+        })
+        return value
     }
 
     const getTenantRoomStatus = async (
@@ -589,24 +647,38 @@ export function matrixService(server: FastifyInstance) {
         const key = normalizeMatrixAliasSeed(options.key || options.name || "allgemein")
         const name = (options.name || "Allgemeiner Chat").trim() || "Allgemeiner Chat"
         const topic = (options.topic || `Allgemeiner Kommunikationsraum für ${tenant.name}`).trim()
+        const cacheKey = `${tenant.id}:${key}`
+        const cachedRoom = matrixTenantRoomCache.get(cacheKey)
+
+        if (cachedRoom?.exists && cachedRoom.cachedUntil > Date.now()) {
+            return cachedRoom.value
+        }
+
         const existing = await getTenantRoomStatus(tenant.id, key, name)
         const userAccount = await provisionCurrentUser(userId, tenant.id)
         const tenantSpace = await provisionCurrentTenantSpace(userId, tenant.id)
 
         if (existing.exists) {
-            return {
+            const value = {
                 ...existing,
                 created: false,
                 alreadyExisted: true,
                 parentSpaceRoomId: tenantSpace.roomId,
                 invitedUserId: userAccount.matrixUserId,
             }
+
+            matrixTenantRoomCache.set(cacheKey, {
+                exists: true,
+                cachedUntil: Date.now() + 30 * 60 * 1000,
+                value,
+            })
+            return value
         }
 
         const serviceLogin = await ensureServiceAccessToken()
         const createdRoom = await requestMatrixJson<{ room_id: string }>(
             "/_matrix/client/v3/createRoom",
-            serviceLogin.access_token,
+            serviceLogin.accessToken,
             {
                 method: "POST",
                 headers: { "Content-Type": "application/json" },
@@ -640,7 +712,7 @@ export function matrixService(server: FastifyInstance) {
 
         await requestMatrixJson(
             `/_matrix/client/v3/rooms/${encodeURIComponent(tenantSpace.roomId)}/state/m.space.child/${encodeURIComponent(createdRoom.room_id)}`,
-            serviceLogin.access_token,
+            serviceLogin.accessToken,
             {
                 method: "PUT",
                 headers: { "Content-Type": "application/json" },
@@ -652,7 +724,7 @@ export function matrixService(server: FastifyInstance) {
             }
         )
 
-        return {
+        const value = {
             tenantId: tenant.id,
             tenantName: tenant.name,
             key,
@@ -664,8 +736,15 @@ export function matrixService(server: FastifyInstance) {
             roomId: createdRoom.room_id,
             parentSpaceRoomId: tenantSpace.roomId,
             invitedUserId: userAccount.matrixUserId,
-            serviceUserId: serviceLogin.user_id,
+            serviceUserId: serviceLogin.matrixUserId,
         }
+
+        matrixTenantRoomCache.set(cacheKey, {
+            exists: true,
+            cachedUntil: Date.now() + 30 * 60 * 1000,
+            value,
+        })
+        return value
     }
 
     const ensureCurrentUserJoinedRoom = async (