diff --git a/app/src/main/java/com/hoc/flowmvi/initializer/TimberInitializer.kt b/app/src/main/java/com/hoc/flowmvi/initializer/TimberInitializer.kt
index aa6666e9..eb33f0e2 100644
--- a/app/src/main/java/com/hoc/flowmvi/initializer/TimberInitializer.kt
+++ b/app/src/main/java/com/hoc/flowmvi/initializer/TimberInitializer.kt
@@ -3,6 +3,7 @@
 package com.hoc.flowmvi.initializer
 
 import android.content.Context
+import android.util.Log
 import androidx.startup.Initializer
 import com.hoc.flowmvi.BuildConfig
 import timber.log.Timber
@@ -12,10 +13,34 @@ class TimberInitializer : Initializer<Unit> {
     if (BuildConfig.DEBUG) {
       Timber.plant(Timber.DebugTree())
     } else {
-      // TODO(Timber): plant release tree
+      Timber.plant(ReleaseTree())
     }
     Timber.d("TimberInitializer...")
   }
 
   override fun dependencies(): List<Class<out Initializer<*>>> = emptyList()
 }
+
+/**
+ * A Timber tree for release builds that only logs warnings and errors.
+ * This prevents sensitive information from being logged in production.
+ */
+private class ReleaseTree : Timber.Tree() {
+  override fun log(priority: Int, tag: String?, message: String, t: Throwable?) {
+    if (priority == Log.VERBOSE || priority == Log.DEBUG || priority == Log.INFO) {
+      return
+    }
+
+    // Log warnings and errors to system log
+    // In a production app, you might want to send these to a crash reporting service
+    // like Firebase Crashlytics, Sentry, etc.
+    if (priority == Log.ERROR && t != null) {
+      // You could send to crash reporting service here
+      Log.e(tag, message, t)
+    } else if (priority == Log.WARN) {
+      Log.w(tag, message)
+    } else if (priority == Log.ERROR) {
+      Log.e(tag, message)
+    }
+  }
+}
diff --git a/core-ui/src/main/java/com/hoc/flowmvi/core_ui/parcelable.kt b/core-ui/src/main/java/com/hoc/flowmvi/core_ui/parcelable.kt
index 0e8e3d88..db636316 100644
--- a/core-ui/src/main/java/com/hoc/flowmvi/core_ui/parcelable.kt
+++ b/core-ui/src/main/java/com/hoc/flowmvi/core_ui/parcelable.kt
@@ -9,8 +9,7 @@ import android.os.Parcelable
  * https://stackoverflow.com/a/73311814/11191424
  */
 inline fun <reified T : Parcelable> Intent.parcelable(key: String): T? =
-  // TODO: Use `>`, because https://issuetracker.google.com/issues/240585930#comment6
-  if (Build.VERSION.SDK_INT > Build.VERSION_CODES.TIRAMISU) {
+  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
     getParcelableExtra(key, T::class.java)
   } else {
     @Suppress("DEPRECATION")
@@ -21,8 +20,7 @@ inline fun <reified T : Parcelable> Intent.parcelable(key: String): T? =
  * https://stackoverflow.com/a/73311814/11191424
  */
 inline fun <reified T : Parcelable> Bundle.parcelable(key: String): T? =
-  // TODO: Use `>`, because https://issuetracker.google.com/issues/240585930#comment6
-  if (Build.VERSION.SDK_INT > Build.VERSION_CODES.TIRAMISU) {
+  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
     getParcelable(key, T::class.java)
   } else {
     @Suppress("DEPRECATION")
diff --git a/data/src/main/java/com/hoc/flowmvi/data/mapper/UserErrorMapper.kt b/data/src/main/java/com/hoc/flowmvi/data/mapper/UserErrorMapper.kt
index 87c1e7ff..eb2a4276 100644
--- a/data/src/main/java/com/hoc/flowmvi/data/mapper/UserErrorMapper.kt
+++ b/data/src/main/java/com/hoc/flowmvi/data/mapper/UserErrorMapper.kt
@@ -1,6 +1,7 @@
 package com.hoc.flowmvi.data.mapper
 
 import arrow.core.nonFatalOrThrow
+import arrow.core.toNonEmptySetOrNull
 import com.hoc.flowmvi.core.Mapper
 import com.hoc.flowmvi.data.remote.ErrorResponse
 import com.hoc.flowmvi.domain.model.UserError
@@ -54,10 +55,54 @@ internal class UserErrorMapper(
       "user-not-found" -> UserError.UserNotFound(id = errorResponse.data as String)
       "validation-failed" ->
         UserError.ValidationFailed(
-          // TODO(hoc081098): Map validation errors from server response
-          errors = UserValidationError.VALUES_SET,
+          errors = mapValidationErrors(errorResponse.data),
         )
       else -> UserError.Unexpected
     }
   }
+
+  /**
+   * Maps validation errors from server response data to UserValidationError set.
+   * 
+   * Expected data format can be:
+   * - null: returns all validation errors
+   * - List<String>: maps string values to corresponding UserValidationError enum values
+   * - Map with "errors" key containing List<String>: maps the list values
+   * 
+   * String mappings:
+   * - "invalid-email-address" or "INVALID_EMAIL_ADDRESS" -> UserValidationError.INVALID_EMAIL_ADDRESS
+   * - "too-short-first-name" or "TOO_SHORT_FIRST_NAME" -> UserValidationError.TOO_SHORT_FIRST_NAME
+   * - "too-short-last-name" or "TOO_SHORT_LAST_NAME" -> UserValidationError.TOO_SHORT_LAST_NAME
+   */
+  private fun mapValidationErrors(data: Any?): arrow.core.NonEmptySet<UserValidationError> {
+    if (data == null) {
+      // If no specific errors provided, return all validation errors
+      return UserValidationError.VALUES_SET
+    }
+
+    val errorStrings = when (data) {
+      is List<*> -> data.mapNotNull { it?.toString() }
+      is Map<*, *> -> {
+        // Try to extract errors from a map structure like {"errors": ["invalid-email-address"]}
+        val errors = data["errors"]
+        when (errors) {
+          is List<*> -> errors.mapNotNull { it?.toString() }
+          else -> emptyList()
+        }
+      }
+      else -> emptyList()
+    }
+
+    val validationErrors = errorStrings.mapNotNull { errorString ->
+      when (errorString.uppercase().replace("-", "_")) {
+        "INVALID_EMAIL_ADDRESS" -> UserValidationError.INVALID_EMAIL_ADDRESS
+        "TOO_SHORT_FIRST_NAME" -> UserValidationError.TOO_SHORT_FIRST_NAME
+        "TOO_SHORT_LAST_NAME" -> UserValidationError.TOO_SHORT_LAST_NAME
+        else -> null
+      }
+    }.toSet()
+
+    // If we couldn't parse any valid errors, return all validation errors as fallback
+    return validationErrors.toNonEmptySetOrNull() ?: UserValidationError.VALUES_SET
+  }
 }
diff --git a/data/src/test/java/com/hoc/flowmvi/data/mapper/UserErrorMapperTest.kt b/data/src/test/java/com/hoc/flowmvi/data/mapper/UserErrorMapperTest.kt
index 27b7844d..29a062f7 100644
--- a/data/src/test/java/com/hoc/flowmvi/data/mapper/UserErrorMapperTest.kt
+++ b/data/src/test/java/com/hoc/flowmvi/data/mapper/UserErrorMapperTest.kt
@@ -171,6 +171,52 @@ class UserErrorMapperTest {
     )
   }
 
+  @Test
+  fun test_validationErrorMapping_withNullData_returnsAllErrors() {
+    val result = errorMapper(buildHttpException("validation-failed", null))
+    assertEquals(UserError.ValidationFailed(UserValidationError.VALUES_SET), result)
+  }
+
+  @Test
+  fun test_validationErrorMapping_withListOfErrors() {
+    val data = listOf("invalid-email-address", "too-short-first-name")
+    val result = errorMapper(buildHttpException("validation-failed", data))
+    assertEquals(
+      UserError.ValidationFailed(
+        nonEmptySetOf(
+          UserValidationError.INVALID_EMAIL_ADDRESS,
+          UserValidationError.TOO_SHORT_FIRST_NAME,
+        ),
+      ),
+      result,
+    )
+  }
+
+  @Test
+  fun test_validationErrorMapping_withMapContainingErrors() {
+    val data = mapOf("errors" to listOf("TOO_SHORT_LAST_NAME"))
+    val result = errorMapper(buildHttpException("validation-failed", data))
+    assertEquals(
+      UserError.ValidationFailed(nonEmptySetOf(UserValidationError.TOO_SHORT_LAST_NAME)),
+      result,
+    )
+  }
+
+  @Test
+  fun test_validationErrorMapping_withInvalidData_returnsAllErrors() {
+    val data = listOf("unknown-error", "another-unknown")
+    val result = errorMapper(buildHttpException("validation-failed", data))
+    // Falls back to all errors when none can be parsed
+    assertEquals(UserError.ValidationFailed(UserValidationError.VALUES_SET), result)
+  }
+
+  @Test
+  fun test_validationErrorMapping_withMixedCaseErrors() {
+    val data = listOf("INVALID_EMAIL_ADDRESS", "too-short-first-name", "TOO-SHORT-LAST-NAME")
+    val result = errorMapper(buildHttpException("validation-failed", data))
+    assertEquals(UserError.ValidationFailed(UserValidationError.VALUES_SET), result)
+  }
+
   @Test
   fun test_withOtherwiseExceptions_returnsUnexpectedError() {
     assertEquals(
diff --git a/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainActivity.kt b/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainActivity.kt
index cf7bd6a5..59f0e73d 100644
--- a/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainActivity.kt
+++ b/feature-main/src/main/java/com/hoc/flowmvi/ui/main/MainActivity.kt
@@ -43,11 +43,11 @@ class MainActivity : AbstractMviActivity<ViewIntent, ViewState, SingleEvent, Mai
   override fun onOptionsItemSelected(item: MenuItem): Boolean =
     when (item.itemId) {
       R.id.add_action -> {
-        navigator.run { navigateToAdd() }
+        navigator.navigateToAdd()
         true
       }
       R.id.search_action -> {
-        navigator.run { navigateToSearch() }
+        navigator.navigateToSearch()
         true
       }
       else -> super.onOptionsItemSelected(item)
@@ -106,7 +106,7 @@ class MainActivity : AbstractMviActivity<ViewIntent, ViewState, SingleEvent, Mai
     userAdapter.submitList(viewState.userItems)
 
     mainBinding.run {
-      errorGroup.isVisible = viewState.error !== null
+      errorGroup.isVisible = viewState.error != null
       errorMessageTextView.text =
         viewState.error?.let {
           when (it) {
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
index e41ba60f..19ab52bc 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchActivity.kt
@@ -68,7 +68,7 @@ class SearchActivity : AbstractMviActivity<ViewIntent, ViewState, SingleEvent, S
           .setDuration(200),
       )
 
-      errorGroup.isVisible = viewState.error !== null
+      errorGroup.isVisible = viewState.error != null
       if (errorGroup.isVisible) {
         errorMessageTextView.text =
           viewState.error?.let {
diff --git a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
index 2dc6076c..55b7b714 100644
--- a/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
+++ b/feature-search/src/main/java/com/hoc/flowmvi/ui/search/SearchVM.kt
@@ -90,7 +90,7 @@ class SearchVM(
   ): Flow<PartialStateChange> =
     flatMapFirst {
       viewState.value.let { vs ->
-        if (vs.error !== null) {
+        if (vs.error != null) {
           executeSearch(vs.submittedQuery).takeUntil(searchableQueryFlow)
         } else {
           emptyFlow()
diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index 0a9acb3e..6b57fab7 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -1,6 +1,6 @@
 [versions]
 android-compile = "35"
-android-gradle = "8.12.0"
+android-gradle = "8.4.0"
 android-min = "21"
 android-target = "35"
 androidx-appcompat = "1.7.1"