diff --git a/backend-lib/src/test/java/cash/z/ecc/android/sdk/internal/model/JniBlockMetaTest.kt b/backend-lib/src/test/java/cash/z/ecc/android/sdk/internal/model/JniBlockMetaTest.kt
new file mode 100644
index 00000000..8194c06a
--- /dev/null
+++ b/backend-lib/src/test/java/cash/z/ecc/android/sdk/internal/model/JniBlockMetaTest.kt
@@ -0,0 +1,32 @@
+package cash.z.ecc.android.sdk.internal.model
+
+import kotlin.test.Test
+import kotlin.test.assertFailsWith
+import kotlin.test.assertIs
+
+class JniBlockMetaTest {
+    @Test
+    fun attributes_within_constraints() {
+        val instance = JniBlockMeta(
+            height = UInt.MAX_VALUE.toLong(),
+            hash = byteArrayOf(),
+            time = 0L,
+            saplingOutputsCount = UInt.MIN_VALUE.toLong(),
+            orchardOutputsCount = UInt.MIN_VALUE.toLong()
+        )
+        assertIs<JniBlockMeta>(instance)
+    }
+
+    @Test
+    fun attributes_not_in_constraints() {
+        assertFailsWith(IllegalArgumentException::class) {
+            JniBlockMeta(
+                height = Long.MAX_VALUE,
+                hash = byteArrayOf(),
+                time = 0L,
+                saplingOutputsCount = Long.MIN_VALUE,
+                orchardOutputsCount = Long.MIN_VALUE
+            )
+        }
+    }
+}
diff --git a/backend-lib/src/test/java/cash/z/ecc/android/sdk/internal/model/JniScanRangeTest.kt b/backend-lib/src/test/java/cash/z/ecc/android/sdk/internal/model/JniScanRangeTest.kt
new file mode 100644
index 00000000..ada935b5
--- /dev/null
+++ b/backend-lib/src/test/java/cash/z/ecc/android/sdk/internal/model/JniScanRangeTest.kt
@@ -0,0 +1,28 @@
+package cash.z.ecc.android.sdk.internal.model
+
+import kotlin.test.Test
+import kotlin.test.assertFailsWith
+import kotlin.test.assertIs
+
+class JniScanRangeTest {
+    @Test
+    fun attributes_within_constraints() {
+        val instance = JniScanRange(
+            startHeight = UInt.MIN_VALUE.toLong(),
+            endHeight = UInt.MAX_VALUE.toLong(),
+            priority = 10
+        )
+        assertIs<JniScanRange>(instance)
+    }
+
+    @Test
+    fun attributes_not_in_constraints() {
+        assertFailsWith(IllegalArgumentException::class) {
+            JniScanRange(
+                startHeight = Long.MIN_VALUE,
+                endHeight = Long.MAX_VALUE,
+                priority = 10
+            )
+        }
+    }
+}
diff --git a/backend-lib/src/test/java/cash/z/ecc/android/sdk/internal/model/JniSubtreeRootTest.kt b/backend-lib/src/test/java/cash/z/ecc/android/sdk/internal/model/JniSubtreeRootTest.kt
new file mode 100644
index 00000000..a9690f6d
--- /dev/null
+++ b/backend-lib/src/test/java/cash/z/ecc/android/sdk/internal/model/JniSubtreeRootTest.kt
@@ -0,0 +1,26 @@
+package cash.z.ecc.android.sdk.internal.model
+
+import kotlin.test.Test
+import kotlin.test.assertFailsWith
+import kotlin.test.assertIs
+
+class JniSubtreeRootTest {
+    @Test
+    fun attributes_within_constraints() {
+        val instance = JniSubtreeRoot(
+            rootHash = byteArrayOf(),
+            completingBlockHeight = UInt.MAX_VALUE.toLong()
+        )
+        assertIs<JniSubtreeRoot>(instance)
+    }
+
+    @Test
+    fun attributes_not_in_constraints() {
+        assertFailsWith(IllegalArgumentException::class) {
+            JniSubtreeRoot(
+                rootHash = byteArrayOf(),
+                completingBlockHeight = Long.MAX_VALUE
+            )
+        }
+    }
+}
diff --git a/demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/fixture/WalletSnapshotFixture.kt b/demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/fixture/WalletSnapshotFixture.kt
index cad402d5..01544e21 100644
--- a/demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/fixture/WalletSnapshotFixture.kt
+++ b/demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/fixture/WalletSnapshotFixture.kt
@@ -1,7 +1,7 @@
 package cash.z.ecc.android.sdk.demoapp.fixture
 
 import cash.z.ecc.android.sdk.Synchronizer
-import cash.z.ecc.android.sdk.block.CompactBlockProcessor
+import cash.z.ecc.android.sdk.block.processor.CompactBlockProcessor
 import cash.z.ecc.android.sdk.demoapp.ui.screen.home.viewmodel.SynchronizerError
 import cash.z.ecc.android.sdk.demoapp.ui.screen.home.viewmodel.WalletSnapshot
 import cash.z.ecc.android.sdk.model.PercentDecimal
diff --git a/demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/ui/screen/home/viewmodel/WalletSnapshot.kt b/demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/ui/screen/home/viewmodel/WalletSnapshot.kt
index 78cb3a01..31d9b1c5 100644
--- a/demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/ui/screen/home/viewmodel/WalletSnapshot.kt
+++ b/demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/ui/screen/home/viewmodel/WalletSnapshot.kt
@@ -1,7 +1,7 @@
 package cash.z.ecc.android.sdk.demoapp.ui.screen.home.viewmodel
 
 import cash.z.ecc.android.sdk.Synchronizer
-import cash.z.ecc.android.sdk.block.CompactBlockProcessor
+import cash.z.ecc.android.sdk.block.processor.CompactBlockProcessor
 import cash.z.ecc.android.sdk.ext.ZcashSdk
 import cash.z.ecc.android.sdk.model.PercentDecimal
 import cash.z.ecc.android.sdk.model.WalletBalance
diff --git a/demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/ui/screen/home/viewmodel/WalletViewModel.kt b/demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/ui/screen/home/viewmodel/WalletViewModel.kt
index e2a55937..a2966530 100644
--- a/demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/ui/screen/home/viewmodel/WalletViewModel.kt
+++ b/demo-app/src/main/java/cash/z/ecc/android/sdk/demoapp/ui/screen/home/viewmodel/WalletViewModel.kt
@@ -7,7 +7,7 @@ import cash.z.ecc.android.bip39.Mnemonics
 import cash.z.ecc.android.bip39.toSeed
 import cash.z.ecc.android.sdk.Synchronizer
 import cash.z.ecc.android.sdk.WalletCoordinator
-import cash.z.ecc.android.sdk.block.CompactBlockProcessor
+import cash.z.ecc.android.sdk.block.processor.CompactBlockProcessor
 import cash.z.ecc.android.sdk.demoapp.getInstance
 import cash.z.ecc.android.sdk.demoapp.preference.EncryptedPreferenceKeys
 import cash.z.ecc.android.sdk.demoapp.preference.EncryptedPreferenceSingleton
diff --git a/sdk-incubator-lib/src/main/java/cash/z/ecc/android/sdk/WalletCoordinator.kt b/sdk-incubator-lib/src/main/java/cash/z/ecc/android/sdk/WalletCoordinator.kt
index da3224f3..9275f16f 100644
--- a/sdk-incubator-lib/src/main/java/cash/z/ecc/android/sdk/WalletCoordinator.kt
+++ b/sdk-incubator-lib/src/main/java/cash/z/ecc/android/sdk/WalletCoordinator.kt
@@ -1,7 +1,7 @@
 package cash.z.ecc.android.sdk
 
 import android.content.Context
-import cash.z.ecc.android.sdk.block.CompactBlockProcessor
+import cash.z.ecc.android.sdk.block.processor.CompactBlockProcessor
 import cash.z.ecc.android.sdk.ext.onFirst
 import cash.z.ecc.android.sdk.internal.Twig
 import cash.z.ecc.android.sdk.model.PersistableWallet
diff --git a/sdk-lib/src/androidTest/java/cash/z/ecc/android/sdk/block/processor/CompactBlockProcessorTest.kt b/sdk-lib/src/androidTest/java/cash/z/ecc/android/sdk/block/processor/CompactBlockProcessorTest.kt
new file mode 100644
index 00000000..54df3b6e
--- /dev/null
+++ b/sdk-lib/src/androidTest/java/cash/z/ecc/android/sdk/block/processor/CompactBlockProcessorTest.kt
@@ -0,0 +1,8 @@
+package cash.z.ecc.android.sdk.block.processor
+
+// TODO [#1094]: Consider fake SDK sync related components
+// TODO [#1094]: Testing the CompactBlockProcessor is only available once we can mock the necessary core components like
+//  [CompactBlockDownloader], [DerivedDataRepository], or [TypesafeBackend]
+// TODO [#1094]: https://github.com/zcash/zcash-android-wallet-sdk/issues/1094
+@Suppress("EmptyClassBlock")
+class CompactBlockProcessorTest
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/SdkSynchronizer.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/SdkSynchronizer.kt
index 05eae408..e2efed16 100644
--- a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/SdkSynchronizer.kt
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/SdkSynchronizer.kt
@@ -5,12 +5,12 @@ import cash.z.ecc.android.sdk.Synchronizer.Status.DISCONNECTED
 import cash.z.ecc.android.sdk.Synchronizer.Status.STOPPED
 import cash.z.ecc.android.sdk.Synchronizer.Status.SYNCED
 import cash.z.ecc.android.sdk.Synchronizer.Status.SYNCING
-import cash.z.ecc.android.sdk.block.CompactBlockProcessor
-import cash.z.ecc.android.sdk.block.CompactBlockProcessor.State.Disconnected
-import cash.z.ecc.android.sdk.block.CompactBlockProcessor.State.Initialized
-import cash.z.ecc.android.sdk.block.CompactBlockProcessor.State.Stopped
-import cash.z.ecc.android.sdk.block.CompactBlockProcessor.State.Synced
-import cash.z.ecc.android.sdk.block.CompactBlockProcessor.State.Syncing
+import cash.z.ecc.android.sdk.block.processor.CompactBlockProcessor
+import cash.z.ecc.android.sdk.block.processor.CompactBlockProcessor.State.Disconnected
+import cash.z.ecc.android.sdk.block.processor.CompactBlockProcessor.State.Initialized
+import cash.z.ecc.android.sdk.block.processor.CompactBlockProcessor.State.Stopped
+import cash.z.ecc.android.sdk.block.processor.CompactBlockProcessor.State.Synced
+import cash.z.ecc.android.sdk.block.processor.CompactBlockProcessor.State.Syncing
 import cash.z.ecc.android.sdk.exception.TransactionEncoderException
 import cash.z.ecc.android.sdk.exception.TransactionSubmitException
 import cash.z.ecc.android.sdk.ext.ConsensusBranchId
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/Synchronizer.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/Synchronizer.kt
index 0745b8bb..ed531c32 100644
--- a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/Synchronizer.kt
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/Synchronizer.kt
@@ -1,7 +1,7 @@
 package cash.z.ecc.android.sdk
 
 import android.content.Context
-import cash.z.ecc.android.sdk.block.CompactBlockProcessor
+import cash.z.ecc.android.sdk.block.processor.CompactBlockProcessor
 import cash.z.ecc.android.sdk.ext.ZcashSdk
 import cash.z.ecc.android.sdk.internal.Derivation
 import cash.z.ecc.android.sdk.internal.SaplingParamTool
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/CompactBlockProcessor.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/CompactBlockProcessor.kt
similarity index 95%
rename from sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/CompactBlockProcessor.kt
rename to sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/CompactBlockProcessor.kt
index fa877c4a..af26c40e 100644
--- a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/CompactBlockProcessor.kt
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/CompactBlockProcessor.kt
@@ -1,8 +1,16 @@
-package cash.z.ecc.android.sdk.block
+package cash.z.ecc.android.sdk.block.processor
 
 import androidx.annotation.VisibleForTesting
 import cash.z.ecc.android.sdk.BuildConfig
 import cash.z.ecc.android.sdk.annotation.OpenForTesting
+import cash.z.ecc.android.sdk.block.processor.model.BatchSyncProgress
+import cash.z.ecc.android.sdk.block.processor.model.GetSubtreeRootsResult
+import cash.z.ecc.android.sdk.block.processor.model.PutSaplingSubtreeRootsResult
+import cash.z.ecc.android.sdk.block.processor.model.SuggestScanRangesResult
+import cash.z.ecc.android.sdk.block.processor.model.SyncStageResult
+import cash.z.ecc.android.sdk.block.processor.model.SyncingResult
+import cash.z.ecc.android.sdk.block.processor.model.UpdateChainTipResult
+import cash.z.ecc.android.sdk.block.processor.model.VerifySuggestedScanRange
 import cash.z.ecc.android.sdk.exception.CompactBlockProcessorException
 import cash.z.ecc.android.sdk.exception.CompactBlockProcessorException.EnhanceTransactionError.EnhanceTxDecryptError
 import cash.z.ecc.android.sdk.exception.CompactBlockProcessorException.EnhanceTransactionError.EnhanceTxDownloadError
@@ -258,8 +266,6 @@ class CompactBlockProcessor internal constructor(
                     }
                     BlockProcessingResult.NoBlocksToProcess -> {
                         setState(State.Synced(_processorInfo.value.overallSyncRange))
-                        // TODO [#1129]: Refactor work with lastSyncRange and lastSyncedHeight
-                        // TODO [#1129]: https://github.com/zcash/zcash-android-wallet-sdk/issues/1129
                         val noWorkDone = _processorInfo.value.overallSyncRange?.isEmpty() ?: true
                         val summary = if (noWorkDone) {
                             "Nothing to process: no new blocks to sync"
@@ -354,34 +360,6 @@ class CompactBlockProcessor internal constructor(
         }
     }
 
-    internal sealed class SuggestScanRangesResult {
-        data class Success(val ranges: List<ScanRange>) : SuggestScanRangesResult()
-        data class Failure(val failedAtHeight: BlockHeight, val exception: Throwable) : SuggestScanRangesResult()
-    }
-
-    internal sealed class GetSubtreeRootsResult {
-        // SbS: Spend-before-Sync
-        data class UseSbS(val subTreeRootList: List<SubtreeRoot>) : GetSubtreeRootsResult()
-        object UseLinear : GetSubtreeRootsResult()
-        object FailureConnection : GetSubtreeRootsResult()
-        data class OtherFailure(val exception: Throwable) : GetSubtreeRootsResult()
-    }
-
-    internal sealed class PutSaplingSubtreeRootsResult {
-        object Success : PutSaplingSubtreeRootsResult()
-        data class Failure(val failedAtHeight: BlockHeight, val exception: Throwable) : PutSaplingSubtreeRootsResult()
-    }
-
-    internal sealed class UpdateChainTipResult {
-        data class Success(val height: BlockHeight) : UpdateChainTipResult()
-        data class Failure(val failedAtHeight: BlockHeight, val exception: Throwable) : UpdateChainTipResult()
-    }
-
-    internal sealed class VerifySuggestedScanRange {
-        data class ShouldVerify(val scanRange: ScanRange) : VerifySuggestedScanRange()
-        object NoRangeToVerify : VerifySuggestedScanRange()
-    }
-
     // TODO [#1137]: Refactor processNewBlocksInSbSOrder
     // TODO [#1137]: https://github.com/zcash/zcash-android-wallet-sdk/issues/1137
     /**
@@ -1192,49 +1170,6 @@ class CompactBlockProcessor internal constructor(
             }
         }
 
-        @VisibleForTesting
-        internal sealed class SyncingResult {
-            object AllSuccess : SyncingResult()
-            data class DownloadSuccess(val downloadedBlocks: List<JniBlockMeta>?) : SyncingResult() {
-                override fun toString(): String {
-                    return "DownloadSuccess with ${downloadedBlocks?.size ?: "none"} blocks"
-                }
-            }
-            interface Failure {
-                val failedAtHeight: BlockHeight
-                val exception: CompactBlockProcessorException
-                fun toBlockProcessingResult(): BlockProcessingResult =
-                    BlockProcessingResult.SyncFailure(
-                        this.failedAtHeight,
-                        this.exception
-                    )
-            }
-            data class DownloadFailed(
-                override val failedAtHeight: BlockHeight,
-                override val exception: CompactBlockProcessorException
-            ) : Failure, SyncingResult()
-            object ScanSuccess : SyncingResult()
-            data class ScanFailed(
-                override val failedAtHeight: BlockHeight,
-                override val exception: CompactBlockProcessorException
-            ) : Failure, SyncingResult()
-            object DeleteSuccess : SyncingResult()
-            data class DeleteFailed(
-                override val failedAtHeight: BlockHeight,
-                override val exception: CompactBlockProcessorException
-            ) : Failure, SyncingResult()
-            object EnhanceSuccess : SyncingResult()
-            data class EnhanceFailed(
-                override val failedAtHeight: BlockHeight,
-                override val exception: CompactBlockProcessorException
-            ) : Failure, SyncingResult()
-            object UpdateBirthday : SyncingResult()
-            data class ContinuityError(
-                override val failedAtHeight: BlockHeight,
-                override val exception: CompactBlockProcessorException
-            ) : Failure, SyncingResult()
-        }
-
         /**
          * Requests, processes and persists all blocks from the given range.
          *
@@ -2034,23 +1969,6 @@ class CompactBlockProcessor internal constructor(
         object Initialized : State()
     }
 
-    /**
-     * Progress model class for sharing the whole batch sync progress out of the sync process.
-     */
-    internal data class BatchSyncProgress(
-        val inRangeOrder: Long = 0,
-        val overallOrder: Long = 0,
-        val resultState: SyncingResult = SyncingResult.AllSuccess
-    )
-
-    /**
-     * Progress model class for sharing particular sync stage result internally in the sync process.
-     */
-    private data class SyncStageResult(
-        val batch: BlockBatch,
-        val stageResult: SyncingResult
-    )
-
     /**
      * Data class for holding detailed information about the processor.
      *
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/BatchSyncProgress.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/BatchSyncProgress.kt
new file mode 100644
index 00000000..4c425bf3
--- /dev/null
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/BatchSyncProgress.kt
@@ -0,0 +1,11 @@
+package cash.z.ecc.android.sdk.block.processor.model
+
+/**
+ * Progress model class for sharing the whole batch synchronization progress out of the synchronization process.
+ */
+internal data class BatchSyncProgress(
+    val inRangeOrder: Long = 0,
+    val overallOrder: Long = 0,
+    val resultState: SyncingResult =
+        SyncingResult.AllSuccess
+)
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/GetSubtreeRootsResult.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/GetSubtreeRootsResult.kt
new file mode 100644
index 00000000..f6fb2f96
--- /dev/null
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/GetSubtreeRootsResult.kt
@@ -0,0 +1,14 @@
+package cash.z.ecc.android.sdk.block.processor.model
+
+import cash.z.ecc.android.sdk.internal.model.SubtreeRoot
+
+/**
+ * Internal class for get subtree roots action result.
+ */
+internal sealed class GetSubtreeRootsResult {
+    // SbS: Spend-before-Sync
+    data class UseSbS(val subTreeRootList: List<SubtreeRoot>) : GetSubtreeRootsResult()
+    object UseLinear : GetSubtreeRootsResult()
+    object FailureConnection : GetSubtreeRootsResult()
+    data class OtherFailure(val exception: Throwable) : GetSubtreeRootsResult()
+}
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/PutSaplingSubtreeRootsResult.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/PutSaplingSubtreeRootsResult.kt
new file mode 100644
index 00000000..d72c4ce6
--- /dev/null
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/PutSaplingSubtreeRootsResult.kt
@@ -0,0 +1,11 @@
+package cash.z.ecc.android.sdk.block.processor.model
+
+import cash.z.ecc.android.sdk.model.BlockHeight
+
+/**
+ * Internal class for sharing put sapling subtree roots action result.
+ */
+internal sealed class PutSaplingSubtreeRootsResult {
+    object Success : PutSaplingSubtreeRootsResult()
+    data class Failure(val failedAtHeight: BlockHeight, val exception: Throwable) : PutSaplingSubtreeRootsResult()
+}
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/SuggestScanRangesResult.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/SuggestScanRangesResult.kt
new file mode 100644
index 00000000..2b886365
--- /dev/null
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/SuggestScanRangesResult.kt
@@ -0,0 +1,12 @@
+package cash.z.ecc.android.sdk.block.processor.model
+
+import cash.z.ecc.android.sdk.internal.model.ScanRange
+import cash.z.ecc.android.sdk.model.BlockHeight
+
+/**
+ * Internal class for sharing suggested scan ranges action result.
+ */
+internal sealed class SuggestScanRangesResult {
+    data class Success(val ranges: List<ScanRange>) : SuggestScanRangesResult()
+    data class Failure(val failedAtHeight: BlockHeight, val exception: Throwable) : SuggestScanRangesResult()
+}
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/SyncStageResult.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/SyncStageResult.kt
new file mode 100644
index 00000000..9195254c
--- /dev/null
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/SyncStageResult.kt
@@ -0,0 +1,11 @@
+package cash.z.ecc.android.sdk.block.processor.model
+
+import cash.z.ecc.android.sdk.internal.model.BlockBatch
+
+/**
+ * Common progress model class for sharing a batch synchronization stage result internally in the synchronization loop.
+ */
+internal data class SyncStageResult(
+    val batch: BlockBatch,
+    val stageResult: SyncingResult
+)
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/SyncingResult.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/SyncingResult.kt
new file mode 100644
index 00000000..6b32a7a5
--- /dev/null
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/SyncingResult.kt
@@ -0,0 +1,51 @@
+package cash.z.ecc.android.sdk.block.processor.model
+
+import cash.z.ecc.android.sdk.block.processor.CompactBlockProcessor
+import cash.z.ecc.android.sdk.exception.CompactBlockProcessorException
+import cash.z.ecc.android.sdk.internal.model.JniBlockMeta
+import cash.z.ecc.android.sdk.model.BlockHeight
+
+/**
+ * Internal class for the overall synchronization process result reporting.
+ */
+internal sealed class SyncingResult {
+    object AllSuccess : SyncingResult()
+    data class DownloadSuccess(val downloadedBlocks: List<JniBlockMeta>?) : SyncingResult() {
+        override fun toString(): String {
+            return "DownloadSuccess with ${downloadedBlocks?.size ?: "none"} blocks"
+        }
+    }
+    interface Failure {
+        val failedAtHeight: BlockHeight
+        val exception: CompactBlockProcessorException
+        fun toBlockProcessingResult(): CompactBlockProcessor.BlockProcessingResult =
+            CompactBlockProcessor.BlockProcessingResult.SyncFailure(
+                this.failedAtHeight,
+                this.exception
+            )
+    }
+    data class DownloadFailed(
+        override val failedAtHeight: BlockHeight,
+        override val exception: CompactBlockProcessorException
+    ) : Failure, SyncingResult()
+    object ScanSuccess : SyncingResult()
+    data class ScanFailed(
+        override val failedAtHeight: BlockHeight,
+        override val exception: CompactBlockProcessorException
+    ) : Failure, SyncingResult()
+    object DeleteSuccess : SyncingResult()
+    data class DeleteFailed(
+        override val failedAtHeight: BlockHeight,
+        override val exception: CompactBlockProcessorException
+    ) : Failure, SyncingResult()
+    object EnhanceSuccess : SyncingResult()
+    data class EnhanceFailed(
+        override val failedAtHeight: BlockHeight,
+        override val exception: CompactBlockProcessorException
+    ) : Failure, SyncingResult()
+    object UpdateBirthday : SyncingResult()
+    data class ContinuityError(
+        override val failedAtHeight: BlockHeight,
+        override val exception: CompactBlockProcessorException
+    ) : Failure, SyncingResult()
+}
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/UpdateChainTipResult.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/UpdateChainTipResult.kt
new file mode 100644
index 00000000..53d218f5
--- /dev/null
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/UpdateChainTipResult.kt
@@ -0,0 +1,11 @@
+package cash.z.ecc.android.sdk.block.processor.model
+
+import cash.z.ecc.android.sdk.model.BlockHeight
+
+/**
+ * Internal class for sharing update chain tip action result.
+ */
+internal sealed class UpdateChainTipResult {
+    data class Success(val height: BlockHeight) : UpdateChainTipResult()
+    data class Failure(val failedAtHeight: BlockHeight, val exception: Throwable) : UpdateChainTipResult()
+}
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/VerifySuggestedScanRange.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/VerifySuggestedScanRange.kt
new file mode 100644
index 00000000..90ed3824
--- /dev/null
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/block/processor/model/VerifySuggestedScanRange.kt
@@ -0,0 +1,11 @@
+package cash.z.ecc.android.sdk.block.processor.model
+
+import cash.z.ecc.android.sdk.internal.model.ScanRange
+
+/**
+ * Internal class for sharing verify suggested scan range action result.
+ */
+internal sealed class VerifySuggestedScanRange {
+    data class ShouldVerify(val scanRange: ScanRange) : VerifySuggestedScanRange()
+    object NoRangeToVerify : VerifySuggestedScanRange()
+}
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/ext/WalletService.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/ext/WalletService.kt
index 786e31d8..743b39df 100644
--- a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/ext/WalletService.kt
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/ext/WalletService.kt
@@ -1,10 +1,8 @@
 package cash.z.ecc.android.sdk.internal.ext
 
-import android.content.Context
 import cash.z.ecc.android.sdk.ext.ZcashSdk.MAX_BACKOFF_INTERVAL
 import cash.z.ecc.android.sdk.internal.Twig
 import kotlinx.coroutines.delay
-import java.io.File
 import kotlin.math.pow
 import kotlin.random.Random
 
@@ -120,12 +118,3 @@ suspend inline fun retryWithBackoff(
         }
     }
 }
-
-/**
- * Return true if the given database already exists.
- *
- * @return true when the given database exists in the given context.
- */
-internal fun dbExists(appContext: Context, dbFileName: String): Boolean {
-    return File(appContext.getDatabasePath(dbFileName).absolutePath).exists()
-}
diff --git a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/model/ScanRange.kt b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/model/ScanRange.kt
index 9ce0973f..39053bf3 100644
--- a/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/model/ScanRange.kt
+++ b/sdk-lib/src/main/java/cash/z/ecc/android/sdk/internal/model/ScanRange.kt
@@ -1,6 +1,5 @@
 package cash.z.ecc.android.sdk.internal.model
 
-import cash.z.ecc.android.sdk.internal.Twig
 import cash.z.ecc.android.sdk.model.BlockHeight
 import cash.z.ecc.android.sdk.model.ZcashNetwork
 
@@ -11,7 +10,6 @@ internal data class ScanRange(
     override fun toString() = "ScanRange(range=$range, priority=${getSuggestScanRangePriority()})"
 
     internal fun getSuggestScanRangePriority(): SuggestScanRangePriority {
-        Twig.verbose { "Current suggested scan range priority: $priority" }
         return SuggestScanRangePriority.values()
             .firstOrNull { it.priority == priority } ?: SuggestScanRangePriority.Scanned
     }
diff --git a/sdk-lib/src/test/java/cash/z/ecc/android/sdk/ext/ExceptionExtTest.kt b/sdk-lib/src/test/java/cash/z/ecc/android/sdk/ext/ExceptionExtTest.kt
index fdb69bd3..1288d9a2 100644
--- a/sdk-lib/src/test/java/cash/z/ecc/android/sdk/ext/ExceptionExtTest.kt
+++ b/sdk-lib/src/test/java/cash/z/ecc/android/sdk/ext/ExceptionExtTest.kt
@@ -1,6 +1,8 @@
 package cash.z.ecc.android.sdk.ext
 
+import cash.z.ecc.android.sdk.internal.ext.BLOCK_HEIGHT_DISCONTINUITY
 import cash.z.ecc.android.sdk.internal.ext.PREV_HASH_MISMATCH
+import cash.z.ecc.android.sdk.internal.ext.TREE_SIZE_MISMATCH
 import cash.z.ecc.android.sdk.internal.ext.isScanContinuityError
 import kotlin.test.Test
 import kotlin.test.assertFalse
@@ -10,15 +12,19 @@ class ExceptionExtTest {
 
     @Test
     fun is_scan_continuity_error() {
-        assertTrue {
-            RuntimeException(PREV_HASH_MISMATCH).isScanContinuityError()
-        }
+        assertTrue { RuntimeException(PREV_HASH_MISMATCH).isScanContinuityError() }
+        assertTrue { RuntimeException(TREE_SIZE_MISMATCH).isScanContinuityError() }
+        assertTrue { RuntimeException(BLOCK_HEIGHT_DISCONTINUITY).isScanContinuityError() }
+
+        assertTrue { RuntimeException(PREV_HASH_MISMATCH.lowercase()).isScanContinuityError() }
+
+        assertTrue { RuntimeException(PREV_HASH_MISMATCH.plus("Text")).isScanContinuityError() }
     }
 
     @Test
     fun is_not_scan_continuity_error() {
-        assertFalse {
-            RuntimeException("Text").isScanContinuityError()
-        }
+        assertFalse { RuntimeException("Text").isScanContinuityError() }
+        assertFalse { RuntimeException("").isScanContinuityError() }
+        assertFalse { RuntimeException(PREV_HASH_MISMATCH.drop(1)).isScanContinuityError() }
     }
 }
diff --git a/sdk-lib/src/test/java/cash/z/ecc/android/sdk/fixture/ScanRangeFixture.kt b/sdk-lib/src/test/java/cash/z/ecc/android/sdk/fixture/ScanRangeFixture.kt
new file mode 100644
index 00000000..249dc099
--- /dev/null
+++ b/sdk-lib/src/test/java/cash/z/ecc/android/sdk/fixture/ScanRangeFixture.kt
@@ -0,0 +1,17 @@
+package cash.z.ecc.android.sdk.fixture
+
+import cash.z.ecc.android.sdk.internal.model.ScanRange
+import cash.z.ecc.android.sdk.internal.model.SuggestScanRangePriority
+import cash.z.ecc.android.sdk.model.BlockHeight
+import cash.z.ecc.android.sdk.model.ZcashNetwork
+
+object ScanRangeFixture {
+    internal val DEFAULT_CLOSED_RANGE =
+        ZcashNetwork.Testnet.saplingActivationHeight..ZcashNetwork.Testnet.saplingActivationHeight + 9
+    internal val DEFAULT_PRIORITY = SuggestScanRangePriority.Verify.priority
+
+    internal fun new(
+        range: ClosedRange<BlockHeight> = DEFAULT_CLOSED_RANGE,
+        priority: Long = DEFAULT_PRIORITY
+    ) = ScanRange(range, priority)
+}
diff --git a/sdk-lib/src/test/java/cash/z/ecc/android/sdk/internal/model/ScanRangeTest.kt b/sdk-lib/src/test/java/cash/z/ecc/android/sdk/internal/model/ScanRangeTest.kt
new file mode 100644
index 00000000..20f6580a
--- /dev/null
+++ b/sdk-lib/src/test/java/cash/z/ecc/android/sdk/internal/model/ScanRangeTest.kt
@@ -0,0 +1,29 @@
+package cash.z.ecc.android.sdk.internal.model
+
+import cash.z.ecc.android.sdk.fixture.ScanRangeFixture
+import cash.z.ecc.android.sdk.internal.ext.isNotEmpty
+import cash.z.ecc.android.sdk.internal.ext.length
+import cash.z.ecc.android.sdk.model.ZcashNetwork
+import kotlin.test.Test
+import kotlin.test.assertTrue
+
+class ScanRangeTest {
+    @Test
+    fun get_suggest_scan_range_priority_test() {
+        val scanRange = ScanRangeFixture.new(
+            priority = SuggestScanRangePriority.Verify.priority
+        )
+        assertTrue {
+            scanRange.getSuggestScanRangePriority() == SuggestScanRangePriority.Verify
+        }
+    }
+
+    @Test
+    fun scan_range_boundaries_test() {
+        val scanRange = ScanRangeFixture.new(
+            range = ZcashNetwork.Testnet.saplingActivationHeight..ZcashNetwork.Testnet.saplingActivationHeight + 9
+        )
+        assertTrue { scanRange.range.isNotEmpty() }
+        assertTrue { scanRange.range.length() == 10L }
+    }
+}