diff --git a/README.md b/README.md
index d35fd17..827e445 100755
--- a/README.md
+++ b/README.md
@@ -35,6 +35,7 @@ Configuration for the application is at config/default.js and config/production.
 - UBAHN_CREATE_TOPIC: Kafka topic for create message
 - UBAHN_UPDATE_TOPIC: Kafka topic for update message
 - UBAHN_DELETE_TOPIC: Kafka topic for delete message
+- UBAHN_AGGREGATE_TOPIC: Kafka topic that is used to combine all create, update and delete message(s)
 - ES.HOST: Elasticsearch host
 - ES.API_VERSION: Elasticsearch API version
 - ES.DOCUMENTS: Elasticsearch index, type and id mapping for resources.
diff --git a/config/default.js b/config/default.js
index 8ae692e..00b208f 100755
--- a/config/default.js
+++ b/config/default.js
@@ -36,6 +36,7 @@ module.exports = {
   UBAHN_CREATE_TOPIC: process.env.UBAHN_CREATE_TOPIC || 'u-bahn.action.create',
   UBAHN_UPDATE_TOPIC: process.env.UBAHN_UPDATE_TOPIC || 'u-bahn.action.update',
   UBAHN_DELETE_TOPIC: process.env.UBAHN_DELETE_TOPIC || 'u-bahn.action.delete',
+  UBAHN_AGGREGATE_TOPIC: process.env.UBAHN_AGGREGATE_TOPIC || 'u-bahn.action.aggregate',
 
   EMSI: {
     CLIENT_ID: process.env.EMSI_CLIENT_ID,
diff --git a/scripts/db/dumpDbToEs.js b/scripts/db/dumpDbToEs.js
index e8218ee..17c51cf 100644
--- a/scripts/db/dumpDbToEs.js
+++ b/scripts/db/dumpDbToEs.js
@@ -11,15 +11,12 @@ const {
 
 async function cleanupES () {
   const client = getESClient()
-  client.indices.delete({
+
+  await client.indices.delete({
     index: '_all'
-  }, function (err, res) {
-    if (err) {
-      console.error(err.message)
-    } else {
-      console.log('Existing indices have been deleted!')
-    }
   })
+
+  console.log('Existing indices have been deleted!')
 }
 
 async function insertIntoES (modelName, body) {
diff --git a/src/common/helper.js b/src/common/helper.js
index e6bda2d..604d0fc 100644
--- a/src/common/helper.js
+++ b/src/common/helper.js
@@ -246,6 +246,12 @@ async function postEvent (topic, payload) {
     payload
   }
   await busApiClient.postEvent(message)
+
+  // Post to the aggregate topic
+  message.payload.originalTopic = topic
+  message.topic = config.UBAHN_AGGREGATE_TOPIC
+  logger.debug(`Posting event to aggregate topic ${message.topic}`)
+  await busApiClient.postEvent(message)
 }
 
 module.exports = {
diff --git a/src/modules/achievement/service.js b/src/modules/achievement/service.js
index e57fcaf..02109fa 100644
--- a/src/modules/achievement/service.js
+++ b/src/modules/achievement/service.js
@@ -12,7 +12,7 @@ const methods = helper.getServiceMethods(
     achievementsProviderId: joi.string().required(),
     name: joi.string().required(),
     uri: joi.string(),
-    certifierId: joi.string(),
+    certifierId: joi.string().allow(''),
     certifiedDate: joi.date().format('iso')
   },
   { // patch request body joi schema
@@ -20,7 +20,7 @@ const methods = helper.getServiceMethods(
     achievementsProviderId: joi.string().required(),
     name: joi.string(),
     uri: joi.string(),
-    certifierId: joi.string(),
+    certifierId: joi.string().allow(''),
     certifiedDate: joi.date().format('iso')
   },
   { // search request query joi schema