diff --git a/services/brig/src/Brig/Index/Options.hs b/services/brig/src/Brig/Index/Options.hs
index dc74ff8e0d2..a7f35739844 100644
--- a/services/brig/src/Brig/Index/Options.hs
+++ b/services/brig/src/Brig/Index/Options.hs
@@ -39,7 +39,7 @@ module Brig.Index.Options
     commandParser,
     mkCreateIndexSettings,
     toESServer,
-    ReindexFromAnotherIndexSettings,
+    ReindexFromAnotherIndexSettings(..),
     reindexDestIndex,
     reindexTimeoutSeconds,
     reindexEsConnection,
diff --git a/services/brig/test/integration/API/Search.hs b/services/brig/test/integration/API/Search.hs
index 7360047f090..07dc351ca06 100644
--- a/services/brig/test/integration/API/Search.hs
+++ b/services/brig/test/integration/API/Search.hs
@@ -1,6 +1,7 @@
 {-# LANGUAGE OverloadedRecordDot #-}
 {-# LANGUAGE PartialTypeSignatures #-}
 {-# LANGUAGE QuasiQuotes #-}
+{-# LANGUAGE RecordWildCards #-}
 -- 'putMapping' is incorrectly deprecated in bloodhound
 {-# OPTIONS_GHC -Wno-deprecations #-}
 {-# OPTIONS_GHC -Wno-incomplete-uni-patterns #-}
@@ -35,12 +36,17 @@ import API.User.Util
 import Bilge
 import Bilge.Assert
 import Brig.App (initHttpManagerWithTLSConfig)
+import Brig.Index.Eval (runCommand)
+import Brig.Index.Options
+import Brig.Index.Options qualified as IndexOpts
+import Brig.Options (ElasticSearchOpts)
 import Brig.Options qualified as Opt
 import Brig.Options qualified as Opts
+import Cassandra qualified as C
+import Cassandra.Options qualified as CassOpts
 import Control.Lens ((.~), (?~), (^.))
-import Control.Monad.Catch (MonadCatch, MonadThrow)
-import Control.Retry
-import Data.Aeson (FromJSON, Value, decode)
+import Control.Monad.Catch (MonadCatch)
+import Data.Aeson (Value, decode)
 import Data.Aeson qualified as Aeson
 import Data.Domain (Domain (Domain))
 import Data.Handle (fromHandle)
@@ -61,6 +67,7 @@ import Network.Wai qualified as Wai
 import Network.Wai.Handler.Warp qualified as Warp
 import Network.Wai.Test qualified as WaiTest
 import Safe (headMay)
+import System.Logger qualified as Log
 import Test.QuickCheck (Arbitrary (arbitrary), generate)
 import Test.Tasty
 import Test.Tasty.HUnit
@@ -68,6 +75,7 @@ import Text.RawString.QQ (r)
 import URI.ByteString qualified as URI
 import UnliftIO (Concurrently (..), async, bracket, cancel, runConcurrently)
 import Util
+import Util.Options (Endpoint)
 import Wire.API.Federation.API.Brig (SearchResponse (SearchResponse))
 import Wire.API.Team.Feature
 import Wire.API.Team.SearchVisibility
@@ -93,7 +101,11 @@ tests opts mgr galley brig = do
         testWithBothIndices opts mgr "Non ascii names" $ testSearchNonAsciiNames brig,
         testWithBothIndices opts mgr "user with umlaut" $ testSearchWithUmlaut brig,
         testWithBothIndices opts mgr "user with japanese name" $ testSearchCJK brig,
-        test mgr "migration to new index" $ testMigrationToNewIndex opts brig,
+        testGroup "index migration" $
+          [ test mgr "migration to new index from existing index" $ testMigrationToNewIndex opts brig runReindexFromAnotherIndex,
+            test mgr "migration to new index from database" $ testMigrationToNewIndex opts brig (runReindexFromDatabase Reindex),
+            test mgr "migration to new index from database (force sync)" $ testMigrationToNewIndex opts brig (runReindexFromDatabase ReindexSameOrNewer)
+          ],
         testGroup "team A: SearchVisibilityStandard (= unrestricted outbound search)" $
           [ testGroup "team A: SearchableByOwnTeam (= restricted inbound search)" $
               [ testWithBothIndices opts mgr "  I. non-team user cannot find team A member by display name" $ testSearchTeamMemberAsNonMemberDisplayName mgr brig galley FeatureStatusDisabled,
@@ -611,8 +623,13 @@ testSearchOtherDomain opts brig = do
 -- cluster. This test spins up a proxy server to pass requests to our only ES
 -- server. The proxy server ensures that only requests to the 'old' index go
 -- through.
-testMigrationToNewIndex :: (TestConstraints m, MonadUnliftIO m) => Opt.Opts -> Brig -> m ()
-testMigrationToNewIndex opts brig = do
+testMigrationToNewIndex ::
+  (TestConstraints m, MonadUnliftIO m) =>
+  Opt.Opts ->
+  Brig ->
+  (Log.Logger -> Opt.Opts -> ES.IndexName -> IO ()) ->
+  m ()
+testMigrationToNewIndex opts brig reindexCommand = do
   withOldESProxy opts $ \oldESUrl oldESIndex -> do
     oldIndexName :: ES.IndexName <- either (\v -> fail ("Invalid index name" ++ Text.unpack v)) pure $ ES.mkIndexName oldESIndex
     let optsOldIndex =
@@ -656,9 +673,10 @@ testMigrationToNewIndex opts brig = do
     assertCanFindByName brig phase1TeamUser1 phase2TeamUser
 
     -- Run Migrations
-    let newIndexName = opts ^. Opt.elasticsearchLens . Opt.indexLens
-    taskNodeId <- assertRight =<< runBH opts (ES.reindexAsync $ ES.mkReindexRequest oldIndexName newIndexName)
-    void $ runBH opts $ waitForTaskToComplete @ES.ReindexResponse taskNodeId
+    logger <- Log.create Log.StdOut
+    liftIO $ do
+      createCommand logger opts oldIndexName
+      reindexCommand logger opts oldIndexName
 
     -- Phase 3: Using old index for search, writing to both indices, migrations have run
     refreshIndex brig
@@ -692,6 +710,71 @@ testMigrationToNewIndex opts brig = do
     assertCanFindByName brig phase1TeamUser1 phase3NonTeamUser
     assertCanFindByName brig phase1TeamUser1 phase3TeamUser
 
+createCommand :: Log.Logger -> Opt.Opts -> ES.IndexName -> IO ()
+createCommand logger opts oldIndexName =
+  let newIndexName = opts ^. Opt.elasticsearchLens . Opt.indexLens
+      esOldOpts :: Opt.ElasticSearchOpts = (opts ^. Opt.elasticsearchLens) & (Opt.indexLens .~ oldIndexName)
+      esOldConnectionSettings :: ESConnectionSettings = toESConnectionSettings esOldOpts
+      esNewConnectionSettings = esOldConnectionSettings {esIndex = newIndexName}
+      replicas = 2
+      shards = 2
+      refreshInterval = 5
+      esSettings =
+        IndexOpts.localElasticSettings
+          & IndexOpts.esConnection .~ esNewConnectionSettings
+          & IndexOpts.esIndexReplicas .~ ES.ReplicaCount replicas
+          & IndexOpts.esIndexShardCount .~ shards
+          & IndexOpts.esIndexRefreshInterval .~ refreshInterval
+   in runCommand logger $ Create esSettings opts.galley
+
+runReindexFromAnotherIndex :: Log.Logger -> Opt.Opts -> ES.IndexName -> IO ()
+runReindexFromAnotherIndex logger opts oldIndexName =
+  let newIndexName = opts ^. Opt.elasticsearchLens . Opt.indexLens
+      esOldOpts :: Opt.ElasticSearchOpts = (opts ^. Opt.elasticsearchLens) & (Opt.indexLens .~ oldIndexName)
+      esOldConnectionSettings :: ESConnectionSettings = toESConnectionSettings esOldOpts
+      reindexSettings = ReindexFromAnotherIndexSettings esOldConnectionSettings newIndexName 5
+   in runCommand logger $ ReindexFromAnotherIndex reindexSettings
+
+runReindexFromDatabase ::
+  (ElasticSettings -> CassandraSettings -> Endpoint -> Command) ->
+  Log.Logger ->
+  Opt.Opts ->
+  ES.IndexName ->
+  IO ()
+runReindexFromDatabase syncCommand logger opts oldIndexName =
+  let newIndexName = opts ^. Opt.elasticsearchLens . Opt.indexLens
+      esOldOpts :: Opt.ElasticSearchOpts = (opts ^. Opt.elasticsearchLens) & (Opt.indexLens .~ oldIndexName)
+      esOldConnectionSettings :: ESConnectionSettings = toESConnectionSettings esOldOpts
+      esNewConnectionSettings = esOldConnectionSettings {esIndex = newIndexName}
+      replicas = 2
+      shards = 2
+      refreshInterval = 5
+      elasticSettings :: ElasticSettings =
+        IndexOpts.localElasticSettings
+          & IndexOpts.esConnection .~ esNewConnectionSettings
+          & IndexOpts.esIndexReplicas .~ ES.ReplicaCount replicas
+          & IndexOpts.esIndexShardCount .~ shards
+          & IndexOpts.esIndexRefreshInterval .~ refreshInterval
+      cassandraSettings :: CassandraSettings =
+        ( localCassandraSettings
+            & IndexOpts.cHost .~ (Text.unpack opts.cassandra.endpoint.host)
+            & IndexOpts.cPort .~ (opts.cassandra.endpoint.port)
+            & IndexOpts.cKeyspace .~ (C.Keyspace opts.cassandra.keyspace)
+        )
+
+      endpoint :: Endpoint = opts.galley
+   in runCommand logger $ syncCommand elasticSettings cassandraSettings endpoint
+
+toESConnectionSettings :: ElasticSearchOpts -> ESConnectionSettings
+toESConnectionSettings opts = ESConnectionSettings {..}
+  where
+    toText (ES.Server url) = url
+    esServer = (fromRight undefined . URI.parseURI URI.strictURIParserOptions . Text.encodeUtf8 . toText) opts.url
+    esIndex = opts.index
+    esCaCert = opts.caCert
+    esInsecureSkipVerifyTls = opts.insecureSkipVerifyTls
+    esCredentials = opts.credentials
+
 withOldESProxy :: (TestConstraints m, MonadUnliftIO m, HasCallStack) => Opt.Opts -> (Text -> Text -> m a) -> m a
 withOldESProxy opts f = do
   indexNameText <- randomHandle
@@ -717,18 +800,6 @@ indexProxyServer idx opts mgr =
             else Wai.WPRResponse (Wai.responseLBS HTTP.status400 [] $ "Refusing to proxy to path=" <> cs (Wai.rawPathInfo req))
    in waiProxyTo proxyApp Wai.defaultOnExc mgr
 
-waitForTaskToComplete :: forall a m. (ES.MonadBH m, MonadThrow m, FromJSON a) => ES.TaskNodeId -> m ()
-waitForTaskToComplete taskNodeId = do
-  let policy = constantDelay 100000 <> limitRetries 30
-  let retryCondition _ = fmap not . isTaskComplete
-  task <- retrying policy retryCondition (const $ ES.tryPerformBHRequest $ ESR.getTask @a taskNodeId)
-  taskCompleted <- isTaskComplete task
-  liftIO $ assertBool "Timed out waiting for task" taskCompleted
-  where
-    isTaskComplete :: Either ES.EsError (ES.TaskResponse a) -> m Bool
-    isTaskComplete (Left e) = liftIO $ assertFailure $ "Expected Right, got Left: " <> show e
-    isTaskComplete (Right taskRes) = pure $ ES.taskResponseCompleted taskRes
-
 testWithBothIndices :: Opt.Opts -> Manager -> TestName -> WaiTest.Session a -> TestTree
 testWithBothIndices opts mgr name f = do
   testGroup