diff --git a/ReactCommon/fabric/mounting/MountingCoordinator.cpp b/ReactCommon/fabric/mounting/MountingCoordinator.cpp
index f4d5f3ab7b8..3ffc83ac1cc 100644
--- a/ReactCommon/fabric/mounting/MountingCoordinator.cpp
+++ b/ReactCommon/fabric/mounting/MountingCoordinator.cpp
@@ -39,7 +39,6 @@ void MountingCoordinator::push(ShadowTreeRevision &&revision) const {
   {
     std::lock_guard<std::mutex> lock(mutex_);
 
-    assert(revision.getNumber() > baseRevision_.getNumber());
     assert(
         !lastRevision_.has_value() ||
         revision.getNumber() != lastRevision_->getNumber());
diff --git a/ReactCommon/fabric/scheduler/Scheduler.cpp b/ReactCommon/fabric/scheduler/Scheduler.cpp
index 14a4f77086c..74c849f77d8 100644
--- a/ReactCommon/fabric/scheduler/Scheduler.cpp
+++ b/ReactCommon/fabric/scheduler/Scheduler.cpp
@@ -79,6 +79,7 @@ Scheduler::Scheduler(
   rootComponentDescriptor_ = std::make_unique<const RootComponentDescriptor>(
       ComponentDescriptorParameters{eventDispatcher, nullptr, nullptr});
 
+  uiManager->setBackgroundExecutor(schedulerToolbox.backgroundExecutor);
   uiManager->setDelegate(this);
   uiManager->setComponentDescriptorRegistry(componentDescriptorRegistry_);
 
diff --git a/ReactCommon/fabric/scheduler/SchedulerToolbox.h b/ReactCommon/fabric/scheduler/SchedulerToolbox.h
index 0f56dbcccb4..f94f410a3c3 100644
--- a/ReactCommon/fabric/scheduler/SchedulerToolbox.h
+++ b/ReactCommon/fabric/scheduler/SchedulerToolbox.h
@@ -10,6 +10,7 @@
 #include <ReactCommon/RuntimeExecutor.h>
 #include <react/componentregistry/ComponentDescriptorFactory.h>
 #include <react/core/EventBeat.h>
+#include <react/uimanager/primitives.h>
 #include <react/utils/ContextContainer.h>
 #include <react/utils/RunLoopObserver.h>
 
@@ -49,6 +50,16 @@ struct SchedulerToolbox final {
    */
   EventBeat::Factory asynchronousEventBeatFactory;
   EventBeat::Factory synchronousEventBeatFactory;
+
+  /*
+   * General-purpose executor that is used to dispatch work on some utility
+   * queue (mostly) asynchronously to avoid unnecessary blocking the caller
+   * queue.
+   * The concrete implementation can use a serial or concurrent queue.
+   * Due to architectural constraints, the concrete implementation *must* call
+   * the call back synchronously if the executor is invoked on the main thread.
+   */
+  BackgroundExecutor backgroundExecutor;
 };
 
 } // namespace react
diff --git a/ReactCommon/fabric/uimanager/UIManager.cpp b/ReactCommon/fabric/uimanager/UIManager.cpp
index f7172002c4c..a5f2554f72f 100644
--- a/ReactCommon/fabric/uimanager/UIManager.cpp
+++ b/ReactCommon/fabric/uimanager/UIManager.cpp
@@ -290,6 +290,11 @@ UIManagerDelegate *UIManager::getDelegate() {
   return delegate_;
 }
 
+void UIManager::setBackgroundExecutor(
+    BackgroundExecutor const &backgroundExecutor) {
+  backgroundExecutor_ = backgroundExecutor;
+}
+
 void UIManager::visitBinding(
     std::function<void(UIManagerBinding const &uiManagerBinding)> callback)
     const {
diff --git a/ReactCommon/fabric/uimanager/UIManager.h b/ReactCommon/fabric/uimanager/UIManager.h
index ab6fdbcca6a..29dda87d431 100644
--- a/ReactCommon/fabric/uimanager/UIManager.h
+++ b/ReactCommon/fabric/uimanager/UIManager.h
@@ -20,6 +20,7 @@
 #include <react/mounting/ShadowTreeRegistry.h>
 #include <react/uimanager/UIManagerAnimationDelegate.h>
 #include <react/uimanager/UIManagerDelegate.h>
+#include <react/uimanager/primitives.h>
 
 namespace facebook {
 namespace react {
@@ -41,6 +42,8 @@ class UIManager final : public ShadowTreeDelegate {
   void setDelegate(UIManagerDelegate *delegate);
   UIManagerDelegate *getDelegate();
 
+  void setBackgroundExecutor(BackgroundExecutor const &backgroundExecutor);
+
   /**
    * Sets and gets the UIManager's Animation APIs delegate.
    * The delegate is stored as a raw pointer, so the owner must null
@@ -143,6 +146,7 @@ class UIManager final : public ShadowTreeDelegate {
   UIManagerAnimationDelegate *animationDelegate_{nullptr};
   UIManagerBinding *uiManagerBinding_;
   ShadowTreeRegistry shadowTreeRegistry_{};
+  BackgroundExecutor backgroundExecutor_{};
 };
 
 } // namespace react
diff --git a/ReactCommon/fabric/uimanager/UIManagerBinding.cpp b/ReactCommon/fabric/uimanager/UIManagerBinding.cpp
index 92d20a915cd..5d9c128d3e8 100644
--- a/ReactCommon/fabric/uimanager/UIManagerBinding.cpp
+++ b/ReactCommon/fabric/uimanager/UIManagerBinding.cpp
@@ -407,20 +407,52 @@ jsi::Value UIManagerBinding::get(
   }
 
   if (methodName == "completeRoot") {
-    return jsi::Function::createFromHostFunction(
-        runtime,
-        name,
-        2,
-        [uiManager](
-            jsi::Runtime &runtime,
-            const jsi::Value &thisValue,
-            const jsi::Value *arguments,
-            size_t count) -> jsi::Value {
-          uiManager->completeSurface(
-              surfaceIdFromValue(runtime, arguments[0]),
-              shadowNodeListFromValue(runtime, arguments[1]));
-          return jsi::Value::undefined();
-        });
+    if (uiManager->backgroundExecutor_) {
+      // Enhanced version of the method that uses `backgroundExecutor` and
+      // captures a shared pointer to `UIManager`.
+      return jsi::Function::createFromHostFunction(
+          runtime,
+          name,
+          2,
+          [uiManager, sharedUIManager = uiManager_](
+              jsi::Runtime &runtime,
+              jsi::Value const &thisValue,
+              jsi::Value const *arguments,
+              size_t count) -> jsi::Value {
+            auto surfaceId = surfaceIdFromValue(runtime, arguments[0]);
+            auto shadowNodeList =
+                shadowNodeListFromValue(runtime, arguments[1]);
+
+            if (sharedUIManager->backgroundExecutor_) {
+              sharedUIManager->backgroundExecutor_(
+                  [sharedUIManager, surfaceId, shadowNodeList] {
+                    sharedUIManager->completeSurface(surfaceId, shadowNodeList);
+                  });
+            } else {
+              uiManager->completeSurface(surfaceId, shadowNodeList);
+            }
+
+            return jsi::Value::undefined();
+          });
+    } else {
+      // Basic version of the method that does *not* use `backgroundExecutor`
+      // and does *not* capture a shared pointer to `UIManager`.
+      return jsi::Function::createFromHostFunction(
+          runtime,
+          name,
+          2,
+          [uiManager](
+              jsi::Runtime &runtime,
+              jsi::Value const &thisValue,
+              jsi::Value const *arguments,
+              size_t count) -> jsi::Value {
+            uiManager->completeSurface(
+                surfaceIdFromValue(runtime, arguments[0]),
+                shadowNodeListFromValue(runtime, arguments[1]));
+
+            return jsi::Value::undefined();
+          });
+    }
   }
 
   if (methodName == "registerEventHandler") {
diff --git a/ReactCommon/fabric/uimanager/primitives.h b/ReactCommon/fabric/uimanager/primitives.h
index f02e8b7ffd6..f5d29a34bb2 100644
--- a/ReactCommon/fabric/uimanager/primitives.h
+++ b/ReactCommon/fabric/uimanager/primitives.h
@@ -16,6 +16,9 @@
 namespace facebook {
 namespace react {
 
+using BackgroundExecutor =
+    std::function<void(std::function<void()> &&callback)>;
+
 struct EventHandlerWrapper : public EventHandler {
   EventHandlerWrapper(jsi::Function eventHandler)
       : callback(std::move(eventHandler)) {}