diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 049944a6b..e438e5b88 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,7 +23,7 @@ jobs:
     outputs:
       build: ${{ steps.ci-target-check.outputs.build }}
       bench: ${{ steps.ci-target-check.outputs.bench }}
-      sharding-test: ${{ steps.ci-target-check.outputs.sharding-test }}
+      complex-test: ${{ steps.ci-target-check.outputs.complex-test }}
 
     steps:
     - name: Checkout code
@@ -42,8 +42,10 @@ jobs:
             - 'admin/**'
             - 'api/converter/**'
           
-          sharding-test:
+          complex-test:
             - 'server/backend/database/**'
+            - 'pkg/document/**'
+            - 'client/**'
 
   build:
     name: build
@@ -109,9 +111,6 @@ jobs:
     - name: Check out code
       uses: actions/checkout@v4
 
-    - name: Get tools dependencies
-      run: make tools
-
     - name: Stack
       run: docker compose -f build/docker/docker-compose.yml up --build -d
 
@@ -136,12 +135,12 @@ jobs:
         github-token: ${{ secrets.GITHUB_TOKEN }}
         comment-always: true
 
-  sharding-test:
-    name: sharding-test
+  complex-test:
+    name: complex-test
     runs-on: ubuntu-latest
 
     needs: ci-target-check
-    if: ${{ needs.ci-target-check.outputs.sharding-test == 'true' }}
+    if: ${{ needs.ci-target-check.outputs.complex-test == 'true' }}
 
     steps:
 
@@ -153,9 +152,6 @@ jobs:
     - name: Check out code
       uses: actions/checkout@v4
 
-    - name: Get tools dependencies
-      run: make tools
-
     - name: Check Docker Compose Version
       run: docker compose --version
 
@@ -177,5 +173,5 @@ jobs:
     - name: Initialize the Mongos
       run: docker compose -f build/docker/sharding/docker-compose.yml exec mongos1 mongosh test /scripts/init-mongos1.js
 
-    - name: Run the tests with sharding tag
-      run: go test -tags sharding -race -v ./test/sharding/...
+    - name: Run the tests with complex tag
+      run: go test -tags complex -race -v ./test/complex/...
diff --git a/test/sharding/server_test.go b/test/complex/main_test.go
similarity index 58%
rename from test/sharding/server_test.go
rename to test/complex/main_test.go
index cd42f0567..9ce84b62d 100644
--- a/test/sharding/server_test.go
+++ b/test/complex/main_test.go
@@ -1,4 +1,4 @@
-//go:build sharding
+//go:build complex
 
 /*
  * Copyright 2023 The Yorkie Authors. All rights reserved.
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-package sharding
+package complex
 
 import (
 	"context"
@@ -27,20 +27,30 @@ import (
 	"testing"
 
 	"connectrpc.com/connect"
-
+	"github.com/stretchr/testify/assert"
 	"github.com/yorkie-team/yorkie/admin"
 	"github.com/yorkie-team/yorkie/api/yorkie/v1/v1connect"
 	"github.com/yorkie-team/yorkie/client"
+	"github.com/yorkie-team/yorkie/pkg/document"
 	"github.com/yorkie-team/yorkie/server/backend"
 	"github.com/yorkie-team/yorkie/server/backend/database"
 	"github.com/yorkie-team/yorkie/server/backend/database/mongo"
 	"github.com/yorkie-team/yorkie/server/backend/housekeeping"
 	"github.com/yorkie-team/yorkie/server/profiling/prometheus"
 	"github.com/yorkie-team/yorkie/server/rpc"
-	"github.com/yorkie-team/yorkie/server/rpc/testcases"
 	"github.com/yorkie-team/yorkie/test/helper"
 )
 
+type testResult struct {
+	flag       bool
+	resultDesc string
+}
+
+type clientAndDocPair struct {
+	cli *client.Client
+	doc *document.Document
+}
+
 var (
 	shardedDBNameForServer   = "test-yorkie-meta-server"
 	testRPCServer            *rpc.Server
@@ -132,82 +142,53 @@ func TestMain(m *testing.M) {
 	os.Exit(code)
 }
 
-func TestSDKRPCServerBackendWithShardedDB(t *testing.T) {
-	t.Run("activate/deactivate client test", func(t *testing.T) {
-		testcases.RunActivateAndDeactivateClientTest(t, testClient)
-	})
-
-	t.Run("attach/detach document test", func(t *testing.T) {
-		testcases.RunAttachAndDetachDocumentTest(t, testClient)
-	})
-
-	t.Run("attach/detach on removed document test", func(t *testing.T) {
-		testcases.RunAttachAndDetachRemovedDocumentTest(t, testClient)
-	})
-
-	t.Run("push/pull changes test", func(t *testing.T) {
-		testcases.RunPushPullChangeTest(t, testClient)
-	})
-
-	t.Run("push/pull on removed document test", func(t *testing.T) {
-		testcases.RunPushPullChangeOnRemovedDocumentTest(t, testClient)
-	})
+func syncClientsThenCheckEqual(t *testing.T, pairs []clientAndDocPair) bool {
+	assert.True(t, len(pairs) > 1)
+	ctx := context.Background()
+	// Save own changes and get previous changes.
+	for i, pair := range pairs {
+		fmt.Printf("before d%d: %s\n", i+1, pair.doc.Marshal())
+		err := pair.cli.Sync(ctx)
+		assert.NoError(t, err)
+	}
 
-	t.Run("remove document test", func(t *testing.T) {
-		testcases.RunRemoveDocumentTest(t, testClient)
-	})
+	// Get last client changes.
+	// Last client get all precede changes in above loop.
+	for _, pair := range pairs[:len(pairs)-1] {
+		err := pair.cli.Sync(ctx)
+		assert.NoError(t, err)
+	}
 
-	t.Run("remove document with invalid client state test", func(t *testing.T) {
-		testcases.RunRemoveDocumentWithInvalidClientStateTest(t, testClient)
-	})
+	// Assert start.
+	expected := pairs[0].doc.Marshal()
+	fmt.Printf("after d1: %s\n", expected)
+	for i, pair := range pairs[1:] {
+		v := pair.doc.Marshal()
+		fmt.Printf("after d%d: %s\n", i+2, v)
+		if expected != v {
+			return false
+		}
+	}
 
-	t.Run("watch document test", func(t *testing.T) {
-		testcases.RunWatchDocumentTest(t, testClient)
-	})
+	return true
 }
 
-func TestAdminRPCServerBackendWithShardedDB(t *testing.T) {
-	t.Run("admin signup test", func(t *testing.T) {
-		testcases.RunAdminSignUpTest(t, testAdminClient)
-	})
+// activeClients creates and activates the given number of clients.
+func activeClients(t *testing.T, n int) (clients []*client.Client) {
+	for i := 0; i < n; i++ {
+		c, err := client.Dial(testRPCAddr)
+		assert.NoError(t, err)
+		assert.NoError(t, c.Activate(context.Background()))
 
-	t.Run("admin login test", func(t *testing.T) {
-		testcases.RunAdminLoginTest(t, testAdminClient)
-	})
-
-	t.Run("admin delete account test", func(t *testing.T) {
-		testcases.RunAdminDeleteAccountTest(t, testAdminClient)
-	})
-
-	t.Run("admin change password test", func(t *testing.T) {
-		testcases.RunAdminChangePasswordTest(t, testAdminClient)
-	})
-
-	t.Run("admin create project test", func(t *testing.T) {
-		testcases.RunAdminCreateProjectTest(t, testAdminClient, testAdminAuthInterceptor)
-	})
-
-	t.Run("admin list projects test", func(t *testing.T) {
-		testcases.RunAdminListProjectsTest(t, testAdminClient, testAdminAuthInterceptor)
-	})
-
-	t.Run("admin get project test", func(t *testing.T) {
-		testcases.RunAdminGetProjectTest(t, testAdminClient, testAdminAuthInterceptor)
-	})
-
-	t.Run("admin update project test", func(t *testing.T) {
-		testcases.RunAdminUpdateProjectTest(t, testAdminClient, testAdminAuthInterceptor)
-	})
-
-	t.Run("admin list documents test", func(t *testing.T) {
-		testcases.RunAdminListDocumentsTest(t, testAdminClient, testAdminAuthInterceptor)
-	})
-
-	t.Run("admin get document test", func(t *testing.T) {
-		testcases.RunAdminGetDocumentTest(t, testClient, testAdminClient, testAdminAuthInterceptor)
-	})
+		clients = append(clients, c)
+	}
+	return
+}
 
-	t.Run("admin list changes test", func(t *testing.T) {
-		testcases.RunAdminListChangesTest(t, testClient, testAdminClient, testAdminAuthInterceptor)
-	})
+// deactivateAndCloseClients deactivates and closes the given clients.
+func deactivateAndCloseClients(t *testing.T, clients []*client.Client) {
+	for _, c := range clients {
+		assert.NoError(t, c.Deactivate(context.Background()))
+		assert.NoError(t, c.Close())
+	}
 }
diff --git a/test/sharding/mongo_client_test.go b/test/complex/mongo_client_test.go
similarity index 99%
rename from test/sharding/mongo_client_test.go
rename to test/complex/mongo_client_test.go
index 5cb2bffe6..2fd6691fb 100644
--- a/test/sharding/mongo_client_test.go
+++ b/test/complex/mongo_client_test.go
@@ -1,4 +1,4 @@
-//go:build sharding
+//go:build complex
 
 /*
  * Copyright 2023 The Yorkie Authors. All rights reserved.
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-package sharding
+package complex
 
 import (
 	"context"
diff --git a/test/complex/server_test.go b/test/complex/server_test.go
new file mode 100644
index 000000000..cacc41186
--- /dev/null
+++ b/test/complex/server_test.go
@@ -0,0 +1,105 @@
+//go:build complex
+
+/*
+ * Copyright 2023 The Yorkie Authors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package complex
+
+import (
+	"testing"
+
+	"github.com/yorkie-team/yorkie/server/rpc/testcases"
+)
+
+func TestSDKRPCServerBackendWithShardedDB(t *testing.T) {
+	t.Run("activate/deactivate client test", func(t *testing.T) {
+		testcases.RunActivateAndDeactivateClientTest(t, testClient)
+	})
+
+	t.Run("attach/detach document test", func(t *testing.T) {
+		testcases.RunAttachAndDetachDocumentTest(t, testClient)
+	})
+
+	t.Run("attach/detach on removed document test", func(t *testing.T) {
+		testcases.RunAttachAndDetachRemovedDocumentTest(t, testClient)
+	})
+
+	t.Run("push/pull changes test", func(t *testing.T) {
+		testcases.RunPushPullChangeTest(t, testClient)
+	})
+
+	t.Run("push/pull on removed document test", func(t *testing.T) {
+		testcases.RunPushPullChangeOnRemovedDocumentTest(t, testClient)
+	})
+
+	t.Run("remove document test", func(t *testing.T) {
+		testcases.RunRemoveDocumentTest(t, testClient)
+	})
+
+	t.Run("remove document with invalid client state test", func(t *testing.T) {
+		testcases.RunRemoveDocumentWithInvalidClientStateTest(t, testClient)
+	})
+
+	t.Run("watch document test", func(t *testing.T) {
+		testcases.RunWatchDocumentTest(t, testClient)
+	})
+}
+
+func TestAdminRPCServerBackendWithShardedDB(t *testing.T) {
+	t.Run("admin signup test", func(t *testing.T) {
+		testcases.RunAdminSignUpTest(t, testAdminClient)
+	})
+
+	t.Run("admin login test", func(t *testing.T) {
+		testcases.RunAdminLoginTest(t, testAdminClient)
+	})
+
+	t.Run("admin delete account test", func(t *testing.T) {
+		testcases.RunAdminDeleteAccountTest(t, testAdminClient)
+	})
+
+	t.Run("admin change password test", func(t *testing.T) {
+		testcases.RunAdminChangePasswordTest(t, testAdminClient)
+	})
+
+	t.Run("admin create project test", func(t *testing.T) {
+		testcases.RunAdminCreateProjectTest(t, testAdminClient, testAdminAuthInterceptor)
+	})
+
+	t.Run("admin list projects test", func(t *testing.T) {
+		testcases.RunAdminListProjectsTest(t, testAdminClient, testAdminAuthInterceptor)
+	})
+
+	t.Run("admin get project test", func(t *testing.T) {
+		testcases.RunAdminGetProjectTest(t, testAdminClient, testAdminAuthInterceptor)
+	})
+
+	t.Run("admin update project test", func(t *testing.T) {
+		testcases.RunAdminUpdateProjectTest(t, testAdminClient, testAdminAuthInterceptor)
+	})
+
+	t.Run("admin list documents test", func(t *testing.T) {
+		testcases.RunAdminListDocumentsTest(t, testAdminClient, testAdminAuthInterceptor)
+	})
+
+	t.Run("admin get document test", func(t *testing.T) {
+		testcases.RunAdminGetDocumentTest(t, testClient, testAdminClient, testAdminAuthInterceptor)
+	})
+
+	t.Run("admin list changes test", func(t *testing.T) {
+		testcases.RunAdminListChangesTest(t, testClient, testAdminClient, testAdminAuthInterceptor)
+	})
+}
diff --git a/test/integration/tree_concurrency_test.go b/test/complex/tree_concurrency_test.go
similarity index 99%
rename from test/integration/tree_concurrency_test.go
rename to test/complex/tree_concurrency_test.go
index b342bebcb..b7e900f5d 100644
--- a/test/integration/tree_concurrency_test.go
+++ b/test/complex/tree_concurrency_test.go
@@ -1,4 +1,4 @@
-//go:build integration
+//go:build complex
 
 /*
  * Copyright 2024 The Yorkie Authors. All rights reserved.
@@ -16,7 +16,7 @@
  * limitations under the License.
  */
 
-package integration
+package complex
 
 import (
 	"context"
@@ -52,11 +52,6 @@ func parseSimpleXML(s string) []string {
 	return res
 }
 
-type testResult struct {
-	flag       bool
-	resultDesc string
-}
-
 type rangeSelector int
 
 const (
diff --git a/test/integration/main_test.go b/test/integration/main_test.go
index e63be3137..d966cf9cf 100644
--- a/test/integration/main_test.go
+++ b/test/integration/main_test.go
@@ -34,6 +34,11 @@ import (
 	"github.com/yorkie-team/yorkie/test/helper"
 )
 
+type testResult struct {
+	flag       bool
+	resultDesc string
+}
+
 type clientAndDocPair struct {
 	cli *client.Client
 	doc *document.Document