diff --git a/packages/react-native/React/Base/RCTBridgeModule.h b/packages/react-native/React/Base/RCTBridgeModule.h
index e0500b6c719..6805512777d 100644
--- a/packages/react-native/React/Base/RCTBridgeModule.h
+++ b/packages/react-native/React/Base/RCTBridgeModule.h
@@ -236,7 +236,7 @@ RCT_EXTERN_C_END
  */
 #define RCT_REMAP_METHOD(js_name, method)       \
   _RCT_EXTERN_REMAP_METHOD(js_name, method, NO) \
-  -(void)method RCT_DYNAMIC;
+  -(void)method RCT_DYNAMIC
 
 /**
  * Similar to RCT_EXPORT_BLOCKING_SYNCHRONOUS_METHOD but lets you set
@@ -248,7 +248,7 @@ RCT_EXTERN_C_END
  */
 #define RCT_REMAP_BLOCKING_SYNCHRONOUS_METHOD(js_name, returnType, method) \
   _RCT_EXTERN_REMAP_METHOD(js_name, method, YES)                           \
-  -(returnType)method RCT_DYNAMIC;
+  -(returnType)method RCT_DYNAMIC
 
 /**
  * Use this macro in a private Objective-C implementation file to automatically
diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/fabric/CoreComponentsRegistry.cpp b/packages/react-native/ReactAndroid/src/main/jni/react/fabric/CoreComponentsRegistry.cpp
index 99ddee8b3b1..fd8e579865f 100644
--- a/packages/react-native/ReactAndroid/src/main/jni/react/fabric/CoreComponentsRegistry.cpp
+++ b/packages/react-native/ReactAndroid/src/main/jni/react/fabric/CoreComponentsRegistry.cpp
@@ -85,14 +85,16 @@ CoreComponentsRegistry::initHybrid(
       [](const EventDispatcher::Weak& eventDispatcher,
          const ContextContainer::Shared& contextContainer)
       -> ComponentDescriptorRegistry::Shared {
+    ComponentDescriptorParameters params{
+        .eventDispatcher = eventDispatcher,
+        .contextContainer = contextContainer,
+        .flavor = nullptr};
+
     auto registry = CoreComponentsRegistry::sharedProviderRegistry()
-                        ->createComponentDescriptorRegistry(
-                            {eventDispatcher, contextContainer});
+                        ->createComponentDescriptorRegistry(params);
     auto& mutableRegistry = const_cast<ComponentDescriptorRegistry&>(*registry);
     mutableRegistry.setFallbackComponentDescriptor(
-        std::make_shared<UnimplementedNativeViewComponentDescriptor>(
-            ComponentDescriptorParameters{
-                eventDispatcher, contextContainer, nullptr}));
+        std::make_shared<UnimplementedNativeViewComponentDescriptor>(params));
 
     return registry;
   };
diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/fabric/FabricMountingManager.cpp b/packages/react-native/ReactAndroid/src/main/jni/react/fabric/FabricMountingManager.cpp
index 75c42d6c5f4..8374141f67f 100644
--- a/packages/react-native/ReactAndroid/src/main/jni/react/fabric/FabricMountingManager.cpp
+++ b/packages/react-native/ReactAndroid/src/main/jni/react/fabric/FabricMountingManager.cpp
@@ -85,7 +85,7 @@ static inline int getIntBufferSizeForType(CppMountItem::Type mountItemType) {
 
 static inline void updateBufferSizes(
     CppMountItem::Type mountItemType,
-    int numInstructions,
+    size_t numInstructions,
     int& batchMountItemIntsSize,
     int& batchMountItemObjectsSize) {
   if (numInstructions == 0) {
@@ -182,7 +182,7 @@ static inline void computeBufferSizes(
 
 static inline void writeIntBufferTypePreamble(
     int mountItemType,
-    int numItems,
+    size_t numItems,
     _JNIEnv* env,
     jintArray& intBufferArray,
     int& intBufferPosition) {
@@ -193,7 +193,7 @@ static inline void writeIntBufferTypePreamble(
     intBufferPosition += 1;
   } else {
     temp[0] = mountItemType | CppMountItem::Type::Multiple;
-    temp[1] = numItems;
+    temp[1] = static_cast<jint>(numItems);
     env->SetIntArrayRegion(intBufferArray, intBufferPosition, 2, temp);
     intBufferPosition += 2;
   }
diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/fabric/ReactNativeConfigHolder.cpp b/packages/react-native/ReactAndroid/src/main/jni/react/fabric/ReactNativeConfigHolder.cpp
index b04187bbbe4..84c3ae5b540 100644
--- a/packages/react-native/ReactAndroid/src/main/jni/react/fabric/ReactNativeConfigHolder.cpp
+++ b/packages/react-native/ReactAndroid/src/main/jni/react/fabric/ReactNativeConfigHolder.cpp
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  */
 
-#import "ReactNativeConfigHolder.h"
+#include "ReactNativeConfigHolder.h"
 
 #include <fbjni/fbjni.h>
 
diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/jni/MethodInvoker.cpp b/packages/react-native/ReactAndroid/src/main/jni/react/jni/MethodInvoker.cpp
index 50f0ba2bb6d..8c0e3ba29dd 100644
--- a/packages/react-native/ReactAndroid/src/main/jni/react/jni/MethodInvoker.cpp
+++ b/packages/react-native/ReactAndroid/src/main/jni/react/jni/MethodInvoker.cpp
@@ -59,7 +59,8 @@ jint extractInteger(const folly::dynamic& value) {
   // The logic here is taken from convertDynamicIfIntegral, but the
   // return type and exception are different.
   if (value.isInt()) {
-    return value.getInt();
+    // TODO: this truncates 64 bit ints, valid in JS
+    return static_cast<jint>(value.getInt());
   }
   double dbl = value.getDouble();
   jint result = static_cast<jint>(dbl);
@@ -227,7 +228,7 @@ MethodCallResult MethodInvoker::invoke(
 
   auto env = Environment::current();
   auto argCount = signature_.size() - 2;
-  JniLocalScope scope(env, argCount);
+  JniLocalScope scope(env, static_cast<int>(argCount));
   jvalue args[argCount];
   std::transform(
       signature_.begin() + 2,
diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/jni/ReadableNativeArray.cpp b/packages/react-native/ReactAndroid/src/main/jni/react/jni/ReadableNativeArray.cpp
index d0d8edb87a7..9add683e2a4 100644
--- a/packages/react-native/ReactAndroid/src/main/jni/react/jni/ReadableNativeArray.cpp
+++ b/packages/react-native/ReactAndroid/src/main/jni/react/jni/ReadableNativeArray.cpp
@@ -23,7 +23,7 @@ void ReadableNativeArray::mapException(std::exception_ptr ex) {
 }
 
 local_ref<JArrayClass<jobject>> ReadableNativeArray::importArray() {
-  jint size = array_.size();
+  auto size = static_cast<jint>(array_.size());
   auto jarray = JArrayClass<jobject>::newArray(size);
   for (jint ii = 0; ii < size; ii++) {
     addDynamicToJArray(jarray, ii, array_.at(ii));
@@ -32,7 +32,7 @@ local_ref<JArrayClass<jobject>> ReadableNativeArray::importArray() {
 }
 
 local_ref<JArrayClass<jobject>> ReadableNativeArray::importTypeArray() {
-  jint size = array_.size();
+  auto size = static_cast<jint>(array_.size());
   auto jarray = JArrayClass<jobject>::newArray(size);
   for (jint ii = 0; ii < size; ii++) {
     (*jarray)[ii] = ReadableType::getType(array_.at(ii).type());
diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/jni/ReadableNativeMap.cpp b/packages/react-native/ReactAndroid/src/main/jni/react/jni/ReadableNativeMap.cpp
index bbd6daab446..08f2b0bebb6 100644
--- a/packages/react-native/ReactAndroid/src/main/jni/react/jni/ReadableNativeMap.cpp
+++ b/packages/react-native/ReactAndroid/src/main/jni/react/jni/ReadableNativeMap.cpp
@@ -80,7 +80,7 @@ local_ref<JArrayClass<jstring>> ReadableNativeMap::importKeys() {
 local_ref<JArrayClass<jobject>> ReadableNativeMap::importValues() {
   throwIfConsumed();
 
-  jint size = keys_.value().size();
+  auto size = static_cast<jint>(keys_.value().size());
   auto jarray = JArrayClass<jobject>::newArray(size);
   for (jint ii = 0; ii < size; ii++) {
     const std::string& key = (*keys_)[ii].getString();
@@ -92,7 +92,7 @@ local_ref<JArrayClass<jobject>> ReadableNativeMap::importValues() {
 local_ref<JArrayClass<jobject>> ReadableNativeMap::importTypes() {
   throwIfConsumed();
 
-  jint size = keys_.value().size();
+  auto size = static_cast<jint>(keys_.value().size());
   auto jarray = JArrayClass<jobject>::newArray(size);
   for (jint ii = 0; ii < size; ii++) {
     const std::string& key = (*keys_)[ii].getString();
diff --git a/packages/react-native/ReactAndroid/src/main/jni/react/newarchdefaults/DefaultComponentsRegistry.cpp b/packages/react-native/ReactAndroid/src/main/jni/react/newarchdefaults/DefaultComponentsRegistry.cpp
index 73bd0392038..f2f9cb031ee 100644
--- a/packages/react-native/ReactAndroid/src/main/jni/react/newarchdefaults/DefaultComponentsRegistry.cpp
+++ b/packages/react-native/ReactAndroid/src/main/jni/react/newarchdefaults/DefaultComponentsRegistry.cpp
@@ -40,15 +40,17 @@ DefaultComponentsRegistry::initHybrid(
       [](const EventDispatcher::Weak& eventDispatcher,
          const ContextContainer::Shared& contextContainer)
       -> ComponentDescriptorRegistry::Shared {
+    ComponentDescriptorParameters params{
+        .eventDispatcher = eventDispatcher,
+        .contextContainer = contextContainer,
+        .flavor = nullptr};
+
     auto registry = DefaultComponentsRegistry::sharedProviderRegistry()
-                        ->createComponentDescriptorRegistry(
-                            {eventDispatcher, contextContainer});
+                        ->createComponentDescriptorRegistry(params);
 
     auto& mutableRegistry = const_cast<ComponentDescriptorRegistry&>(*registry);
     mutableRegistry.setFallbackComponentDescriptor(
-        std::make_shared<UnimplementedNativeViewComponentDescriptor>(
-            ComponentDescriptorParameters{
-                eventDispatcher, contextContainer, nullptr}));
+        std::make_shared<UnimplementedNativeViewComponentDescriptor>(params));
 
     return registry;
   };
diff --git a/packages/react-native/ReactCommon/cxxreact/JSBigString.cpp b/packages/react-native/ReactCommon/cxxreact/JSBigString.cpp
index 7ca8e18bfd8..eaa305c238e 100644
--- a/packages/react-native/ReactCommon/cxxreact/JSBigString.cpp
+++ b/packages/react-native/ReactCommon/cxxreact/JSBigString.cpp
@@ -38,8 +38,8 @@ JSBigFileString::JSBigFileString(int fd, size_t size, off_t offset /*= 0*/)
     const static auto ps = sysconf(_SC_PAGESIZE);
     auto d = lldiv(offset, ps);
 
-    m_mapOff = d.quot;
-    m_pageOff = d.rem;
+    m_mapOff = static_cast<off_t>(d.quot);
+    m_pageOff = static_cast<off_t>(d.rem);
     m_size = size + m_pageOff;
   } else {
     m_mapOff = 0;
diff --git a/packages/react-native/ReactCommon/react/nativemodule/core/platform/android/ReactCommon/JavaTurboModule.cpp b/packages/react-native/ReactCommon/react/nativemodule/core/platform/android/ReactCommon/JavaTurboModule.cpp
index a28b38fa1de..03a60f9bdac 100644
--- a/packages/react-native/ReactCommon/react/nativemodule/core/platform/android/ReactCommon/JavaTurboModule.cpp
+++ b/packages/react-native/ReactCommon/react/nativemodule/core/platform/android/ReactCommon/JavaTurboModule.cpp
@@ -250,13 +250,15 @@ JNIArgs convertJSIArgsToJNIArgs(
     size_t count,
     const std::shared_ptr<CallInvoker>& jsInvoker,
     TurboModuleMethodValueKind valueKind) {
-  unsigned int expectedArgumentCount = valueKind == PromiseKind
+  size_t expectedArgumentCount = valueKind == PromiseKind
       ? methodArgTypes.size() - 1
       : methodArgTypes.size();
 
   if (expectedArgumentCount != count) {
     throw JavaTurboModuleInvalidArgumentCountException(
-        methodName, count, expectedArgumentCount);
+        methodName,
+        static_cast<int>(count),
+        static_cast<int>(expectedArgumentCount));
   }
 
   JNIArgs jniArgs(valueKind == PromiseKind ? count + 1 : count);
@@ -505,7 +507,8 @@ jsi::Value JavaTurboModule::invokeJavaMethod(
    * GlobalReferences. The LocalReferences are then promptly deleted
    * after the conversion.
    */
-  unsigned int actualArgCount = valueKind == VoidKind ? 0 : argCount;
+  unsigned int actualArgCount =
+      valueKind == VoidKind ? 0 : static_cast<unsigned int>(argCount);
   unsigned int estimatedLocalRefCount =
       actualArgCount + maxReturnObjects + buffer;
 
diff --git a/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTInteropTurboModule.h b/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTInteropTurboModule.h
index 914153bff44..63105fe61ce 100644
--- a/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTInteropTurboModule.h
+++ b/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTInteropTurboModule.h
@@ -23,7 +23,7 @@ class JSI_EXPORT ObjCInteropTurboModule : public ObjCTurboModule {
   struct MethodDescriptor {
     std::string methodName;
     SEL selector;
-    int jsArgCount;
+    size_t jsArgCount;
     TurboModuleMethodValueKind jsReturnKind;
   };
 
diff --git a/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTInteropTurboModule.mm b/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTInteropTurboModule.mm
index 9bd3395d37d..ad267de8113 100644
--- a/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTInteropTurboModule.mm
+++ b/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTInteropTurboModule.mm
@@ -192,11 +192,11 @@ ObjCInteropTurboModule::ObjCInteropTurboModule(const ObjCTurboModule::InitParams
   methodArgumentTypeNames_ = methodArgTypeNames;
 
   for (const ExportedMethod &method : methods) {
-    const int numArgs = [method.argumentTypes count];
+    const size_t numArgs = [method.argumentTypes count];
     const bool isPromiseMethod =
         numArgs >= 2 && [method.argumentTypes[numArgs - 1] isEqualToString:@"RCTPromiseRejectBlock"];
 
-    const int jsArgCount = isPromiseMethod ? numArgs - 2 : numArgs;
+    const size_t jsArgCount = isPromiseMethod ? numArgs - 2 : numArgs;
 
     /**
      * In the TurboModule system, only promises and voids are special. So, set those.
@@ -330,7 +330,7 @@ void ObjCInteropTurboModule::setInvocationArg(
   NSString *methodName = @(methodNameCStr);
   std::string methodJsSignature = name_ + "." + methodNameCStr + "()";
 
-  NSString *argumentType = getArgumentTypeName(runtime, methodName, index);
+  NSString *argumentType = getArgumentTypeName(runtime, methodName, static_cast<int>(index));
   std::string errorPrefix = methodJsSignature + ": Error while converting JavaScript argument " +
       std::to_string(index) + " to Objective C type " + [argumentType UTF8String] + ". ";
 
@@ -586,7 +586,7 @@ NSString *ObjCInteropTurboModule::getArgumentTypeName(jsi::Runtime &runtime, NSS
   }
 
   if ([methodArgumentTypeNames_[methodName] count] <= argIndex) {
-    int paramCount = [methodArgumentTypeNames_[methodName] count];
+    size_t paramCount = [methodArgumentTypeNames_[methodName] count];
     throw jsi::JSError(runtime, errorPrefix + "Method has only " + std::to_string(paramCount) + " parameter types.");
   }
 
diff --git a/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModule.h b/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModule.h
index 08feeb6ffef..b5e47efec6c 100644
--- a/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModule.h
+++ b/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModule.h
@@ -62,7 +62,7 @@ class JSI_EXPORT ObjCTurboModule : public TurboModule {
   std::shared_ptr<NativeMethodCallInvoker> nativeMethodCallInvoker_;
 
  protected:
-  void setMethodArgConversionSelector(NSString *methodName, int argIndex, NSString *fnName);
+  void setMethodArgConversionSelector(NSString *methodName, size_t argIndex, NSString *fnName);
 
   /**
    * Why is this virtual?
@@ -126,8 +126,8 @@ class JSI_EXPORT ObjCTurboModule : public TurboModule {
   NSDictionary<NSString *, NSArray<NSString *> *> *methodArgumentTypeNames_;
 
   bool isMethodSync(TurboModuleMethodValueKind returnType);
-  BOOL hasMethodArgConversionSelector(NSString *methodName, int argIndex);
-  SEL getMethodArgConversionSelector(NSString *methodName, int argIndex);
+  BOOL hasMethodArgConversionSelector(NSString *methodName, size_t argIndex);
+  SEL getMethodArgConversionSelector(NSString *methodName, size_t argIndex);
   NSInvocation *createMethodInvocation(
       jsi::Runtime &runtime,
       bool isSync,
diff --git a/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModule.mm b/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModule.mm
index f7dd5468a11..be0846fff24 100644
--- a/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModule.mm
+++ b/packages/react-native/ReactCommon/react/nativemodule/core/platform/ios/ReactCommon/RCTTurboModule.mm
@@ -595,7 +595,7 @@ void ObjCTurboModule::setInvocationArg(
      * Convert objects using RCTConvert.
      */
     if (objCArgType == @encode(id)) {
-      NSString *argumentType = getArgumentTypeName(runtime, methodNameNSString, i);
+      NSString *argumentType = getArgumentTypeName(runtime, methodNameNSString, static_cast<int>(i));
       if (argumentType != nil) {
         NSString *rctConvertMethodName = [NSString stringWithFormat:@"%@:", argumentType];
         SEL rctConvertSelector = NSSelectorFromString(rctConvertMethodName);
@@ -776,19 +776,19 @@ jsi::Value ObjCTurboModule::invokeObjCMethod(
   return returnValue;
 }
 
-BOOL ObjCTurboModule::hasMethodArgConversionSelector(NSString *methodName, int argIndex)
+BOOL ObjCTurboModule::hasMethodArgConversionSelector(NSString *methodName, size_t argIndex)
 {
   return methodArgConversionSelectors_ && methodArgConversionSelectors_[methodName] &&
       ![methodArgConversionSelectors_[methodName][argIndex] isEqual:[NSNull null]];
 }
 
-SEL ObjCTurboModule::getMethodArgConversionSelector(NSString *methodName, int argIndex)
+SEL ObjCTurboModule::getMethodArgConversionSelector(NSString *methodName, size_t argIndex)
 {
   assert(hasMethodArgConversionSelector(methodName, argIndex));
   return (SEL)((NSValue *)methodArgConversionSelectors_[methodName][argIndex]).pointerValue;
 }
 
-void ObjCTurboModule::setMethodArgConversionSelector(NSString *methodName, int argIndex, NSString *fnName)
+void ObjCTurboModule::setMethodArgConversionSelector(NSString *methodName, size_t argIndex, NSString *fnName)
 {
   if (!methodArgConversionSelectors_) {
     methodArgConversionSelectors_ = [NSMutableDictionary new];
diff --git a/packages/react-native/ReactCommon/react/renderer/attributedstring/conversions.h b/packages/react-native/ReactCommon/react/renderer/attributedstring/conversions.h
index 445e452e1f4..fd3dedfc585 100644
--- a/packages/react-native/ReactCommon/react/renderer/attributedstring/conversions.h
+++ b/packages/react-native/ReactCommon/react/renderer/attributedstring/conversions.h
@@ -1162,9 +1162,10 @@ inline MapBuffer toMapBuffer(const AttributedString& attributedString) {
   }
 
   auto builder = MapBufferBuilder();
-  builder.putInt(
-      AS_KEY_HASH,
-      std::hash<facebook::react::AttributedString>{}(attributedString));
+  size_t hash =
+      std::hash<facebook::react::AttributedString>{}(attributedString);
+  // TODO: This truncates half the hash
+  builder.putInt(AS_KEY_HASH, static_cast<int>(hash));
   builder.putString(AS_KEY_STRING, attributedString.getString());
   auto fragmentsMap = fragmentsBuilder.build();
   builder.putMapBuffer(AS_KEY_FRAGMENTS, fragmentsMap);
diff --git a/packages/react-native/ReactCommon/react/renderer/components/legacyviewmanagerinterop/RCTLegacyViewManagerInteropCoordinator.mm b/packages/react-native/ReactCommon/react/renderer/components/legacyviewmanagerinterop/RCTLegacyViewManagerInteropCoordinator.mm
index 92b53de7838..ea8222b2e81 100644
--- a/packages/react-native/ReactCommon/react/renderer/components/legacyviewmanagerinterop/RCTLegacyViewManagerInteropCoordinator.mm
+++ b/packages/react-native/ReactCommon/react/renderer/components/legacyviewmanagerinterop/RCTLegacyViewManagerInteropCoordinator.mm
@@ -46,7 +46,7 @@ using namespace facebook::react;
 - (instancetype)initWithComponentData:(RCTComponentData *)componentData
                                bridge:(nullable RCTBridge *)bridge
                           bridgeProxy:(nullable RCTBridgeProxy *)bridgeProxy
-                bridgelessInteropData:(RCTBridgeModuleDecorator *)bridgelessInteropData;
+                bridgelessInteropData:(RCTBridgeModuleDecorator *)bridgelessInteropData
 {
   if (self = [super init]) {
     _componentData = componentData;
@@ -89,7 +89,7 @@ using namespace facebook::react;
   [_eventInterceptors removeObjectForKey:[NSNumber numberWithInteger:tag]];
 }
 
-- (UIView *)createPaperViewWithTag:(NSInteger)tag;
+- (UIView *)createPaperViewWithTag:(NSInteger)tag
 {
   UIView *view = [_componentData createViewWithTag:[NSNumber numberWithInteger:tag] rootTag:NULL];
   [_bridgelessInteropData attachInteropAPIsToModule:(id<RCTBridgeModule>)_componentData.bridgelessViewManager];
diff --git a/packages/react-native/ReactCommon/react/renderer/components/textinput/platform/android/react/renderer/components/androidtextinput/AndroidTextInputState.cpp b/packages/react-native/ReactCommon/react/renderer/components/textinput/platform/android/react/renderer/components/androidtextinput/AndroidTextInputState.cpp
index ab5516d796e..07cbddf59f4 100644
--- a/packages/react-native/ReactCommon/react/renderer/components/textinput/platform/android/react/renderer/components/androidtextinput/AndroidTextInputState.cpp
+++ b/packages/react-native/ReactCommon/react/renderer/components/textinput/platform/android/react/renderer/components/androidtextinput/AndroidTextInputState.cpp
@@ -88,7 +88,10 @@ MapBuffer AndroidTextInputState::getMapBuffer() const {
   auto builder = MapBufferBuilder();
   // See comment in getDynamic block.
   if (cachedAttributedStringId == 0) {
-    builder.putInt(TX_STATE_KEY_MOST_RECENT_EVENT_COUNT, mostRecentEventCount);
+    // TODO truncation
+    builder.putInt(
+        TX_STATE_KEY_MOST_RECENT_EVENT_COUNT,
+        static_cast<int32_t>(mostRecentEventCount));
 
     auto attStringMapBuffer = toMapBuffer(attributedString);
     builder.putMapBuffer(TX_STATE_KEY_ATTRIBUTED_STRING, attStringMapBuffer);
diff --git a/packages/react-native/ReactCommon/react/renderer/components/textinput/platform/ios/react/renderer/components/iostextinput/TextInputShadowNode.cpp b/packages/react-native/ReactCommon/react/renderer/components/textinput/platform/ios/react/renderer/components/iostextinput/TextInputShadowNode.cpp
index 462456335ca..dad61c26f2f 100644
--- a/packages/react-native/ReactCommon/react/renderer/components/textinput/platform/ios/react/renderer/components/iostextinput/TextInputShadowNode.cpp
+++ b/packages/react-native/ReactCommon/react/renderer/components/textinput/platform/ios/react/renderer/components/iostextinput/TextInputShadowNode.cpp
@@ -60,8 +60,11 @@ AttributedString TextInputShadowNode::getAttributedString(
       layoutContext.fontSizeMultiplier);
   auto attributedString = AttributedString{};
 
-  attributedString.appendFragment(
-      AttributedString::Fragment{getConcreteProps().text, textAttributes});
+  attributedString.appendFragment(AttributedString::Fragment{
+      .string = getConcreteProps().text,
+      .textAttributes = textAttributes,
+      // TODO: Is this really meant to be by value?
+      .parentShadowView = ShadowView{}});
 
   auto attachments = Attachments{};
   BaseTextShadowNode::buildAttributedString(
diff --git a/packages/react-native/ReactCommon/react/renderer/components/view/platform/android/react/renderer/components/view/AccessibilityPropsMapBuffer.cpp b/packages/react-native/ReactCommon/react/renderer/components/view/platform/android/react/renderer/components/view/AccessibilityPropsMapBuffer.cpp
index 47a0012c9ea..1a53e2dc113 100644
--- a/packages/react-native/ReactCommon/react/renderer/components/view/platform/android/react/renderer/components/view/AccessibilityPropsMapBuffer.cpp
+++ b/packages/react-native/ReactCommon/react/renderer/components/view/platform/android/react/renderer/components/view/AccessibilityPropsMapBuffer.cpp
@@ -12,7 +12,7 @@ namespace facebook::react {
 
 static MapBuffer convertAccessibilityActions(
     const std::vector<AccessibilityAction>& actions) {
-  MapBufferBuilder builder(actions.size());
+  MapBufferBuilder builder(static_cast<uint32_t>(actions.size()));
   for (auto i = 0; i < actions.size(); i++) {
     const auto& action = actions[i];
     MapBufferBuilder actionsBuilder(2);
@@ -28,7 +28,7 @@ static MapBuffer convertAccessibilityActions(
 
 static MapBuffer convertAccessibilityLabelledBy(
     const AccessibilityLabelledBy& labelledBy) {
-  MapBufferBuilder builder(labelledBy.value.size());
+  MapBufferBuilder builder(static_cast<uint32_t>(labelledBy.value.size()));
   for (auto i = 0; i < labelledBy.value.size(); i++) {
     builder.putString(i, labelledBy.value[i]);
   }
diff --git a/packages/react-native/ReactCommon/react/renderer/mapbuffer/MapBufferBuilder.cpp b/packages/react-native/ReactCommon/react/renderer/mapbuffer/MapBufferBuilder.cpp
index e2ca2d57f43..7bf76d91e69 100644
--- a/packages/react-native/ReactCommon/react/renderer/mapbuffer/MapBufferBuilder.cpp
+++ b/packages/react-native/ReactCommon/react/renderer/mapbuffer/MapBufferBuilder.cpp
@@ -116,18 +116,18 @@ void MapBufferBuilder::putMapBuffer(MapBuffer::Key key, const MapBuffer& map) {
 void MapBufferBuilder::putMapBufferList(
     MapBuffer::Key key,
     const std::vector<MapBuffer>& mapBufferList) {
-  int32_t offset = dynamicData_.size();
+  auto offset = static_cast<int32_t>(dynamicData_.size());
   int32_t dataSize = 0;
   for (const MapBuffer& mapBuffer : mapBufferList) {
-    dataSize = dataSize + INT_SIZE + mapBuffer.size();
+    dataSize = dataSize + INT_SIZE + static_cast<int32_t>(mapBuffer.size());
   }
 
   dynamicData_.resize(offset + INT_SIZE, 0);
   memcpy(dynamicData_.data() + offset, &dataSize, INT_SIZE);
 
   for (const MapBuffer& mapBuffer : mapBufferList) {
-    int32_t mapBufferSize = mapBuffer.size();
-    int32_t dynamicDataSize = dynamicData_.size();
+    auto mapBufferSize = static_cast<int32_t>(mapBuffer.size());
+    auto dynamicDataSize = static_cast<int32_t>(dynamicData_.size());
     dynamicData_.resize(dynamicDataSize + INT_SIZE + mapBufferSize, 0);
     // format [length of buffer (int)] + [bytes of MapBuffer]
     memcpy(dynamicData_.data() + dynamicDataSize, &mapBufferSize, INT_SIZE);
diff --git a/packages/react-native/ReactCommon/react/renderer/mapbuffer/MapBufferBuilder.h b/packages/react-native/ReactCommon/react/renderer/mapbuffer/MapBufferBuilder.h
index 0b26e915aea..60ca37d20ab 100644
--- a/packages/react-native/ReactCommon/react/renderer/mapbuffer/MapBufferBuilder.h
+++ b/packages/react-native/ReactCommon/react/renderer/mapbuffer/MapBufferBuilder.h
@@ -27,6 +27,8 @@ class MapBufferBuilder {
 
   void putInt(MapBuffer::Key key, int32_t value);
 
+  // TODO: Support 64 bit integers
+
   void putBool(MapBuffer::Key key, bool value);
 
   void putDouble(MapBuffer::Key key, double value);
diff --git a/packages/react-native/ReactCommon/react/renderer/mounting/ShadowTree.cpp b/packages/react-native/ReactCommon/react/renderer/mounting/ShadowTree.cpp
index 1b98aac8ce0..1461f894b93 100644
--- a/packages/react-native/ReactCommon/react/renderer/mounting/ShadowTree.cpp
+++ b/packages/react-native/ReactCommon/react/renderer/mounting/ShadowTree.cpp
@@ -427,7 +427,7 @@ CommitStatus ShadowTree::tryCommit(
   telemetry.setAsThreadLocal();
   newRootShadowNode->layoutIfNeeded(&affectedLayoutableNodes);
   telemetry.unsetAsThreadLocal();
-  telemetry.didLayout(affectedLayoutableNodes.size());
+  telemetry.didLayout(static_cast<int>(affectedLayoutableNodes.size()));
 
   {
     // Updating `currentRevision_` in unique manner if it hasn't changed.
diff --git a/packages/react-native/ReactCommon/react/renderer/uimanager/UIManager.cpp b/packages/react-native/ReactCommon/react/renderer/uimanager/UIManager.cpp
index 0853110a3a0..e88f56f64c2 100644
--- a/packages/react-native/ReactCommon/react/renderer/uimanager/UIManager.cpp
+++ b/packages/react-native/ReactCommon/react/renderer/uimanager/UIManager.cpp
@@ -173,8 +173,8 @@ void UIManager::completeSurface(
           return std::make_shared<RootShadowNode>(
               oldRootShadowNode,
               ShadowNodeFragment{
-                  /* .props = */ ShadowNodeFragment::propsPlaceholder(),
-                  /* .children = */ rootChildren,
+                  .props = ShadowNodeFragment::propsPlaceholder(),
+                  .children = rootChildren,
               });
         },
         commitOptions);
diff --git a/packages/react-native/ReactCommon/react/renderer/uimanager/UIManagerBinding.cpp b/packages/react-native/ReactCommon/react/renderer/uimanager/UIManagerBinding.cpp
index 4f3ac236e6e..77fac8ee516 100644
--- a/packages/react-native/ReactCommon/react/renderer/uimanager/UIManagerBinding.cpp
+++ b/packages/react-native/ReactCommon/react/renderer/uimanager/UIManagerBinding.cpp
@@ -501,8 +501,9 @@ jsi::Value UIManagerBinding::get(
             uiManager->completeSurface(
                 surfaceId,
                 shadowNodeList,
-                {/* .enableStateReconciliation = */ true,
-                 /* .mountSynchronously = */ false});
+                {.enableStateReconciliation = true,
+                 .mountSynchronously = false,
+                 .shouldYield = nullptr});
           } else {
             auto weakShadowNodeList =
                 weakShadowNodeListFromValue(runtime, arguments[1]);
diff --git a/packages/react-native/ReactCommon/react/runtime/TimerManager.h b/packages/react-native/ReactCommon/react/runtime/TimerManager.h
index 6735e29c55a..49e54684d49 100644
--- a/packages/react-native/ReactCommon/react/runtime/TimerManager.h
+++ b/packages/react-native/ReactCommon/react/runtime/TimerManager.h
@@ -104,7 +104,7 @@ class TimerManager {
 
   // Each timeout that is registered on this queue gets a sequential id.  This
   // is the global count from which those are assigned.
-  uint64_t timerIndex_{0};
+  uint32_t timerIndex_{0};
 
   // The React Native microtask queue is used to back public APIs including
   // `queueMicrotask`, `clearImmediate`, and `setImmediate` (which is used by