diff --git a/app_dart/lib/src/model/appengine/commit.dart b/app_dart/lib/src/model/appengine/commit.dart
index 4fa9eb4..592934e 100644
--- a/app_dart/lib/src/model/appengine/commit.dart
+++ b/app_dart/lib/src/model/appengine/commit.dart
@@ -6,6 +6,8 @@
 import 'package:github/github.dart';
 import 'package:json_annotation/json_annotation.dart';
 
+import '../../service/datastore.dart';
+import '../../service/logging.dart';
 import 'key_converter.dart';
 
 part 'commit.g.dart';
@@ -28,6 +30,28 @@
     id = key?.id;
   }
 
+  /// Create a [Key] that can be used to lookup a [Commit] from Datastore.
+  static Key<String> createKey({
+    required DatastoreDB db,
+    required RepositorySlug slug,
+    required String gitBranch,
+    required String sha,
+  }) {
+    return db.emptyKey.append(
+      Commit,
+      id: '${slug.fullName}/$gitBranch/$sha',
+    );
+  }
+
+  /// Lookup [Commit] from Datastore.
+  static Future<Commit> fromDatastore({
+    required DatastoreService datastore,
+    required Key<String> key,
+  }) async {
+    log.fine('Looking up commit by key with id: ${key.id}');
+    return datastore.lookupByValue<Commit>(key);
+  }
+
   /// The timestamp (in milliseconds since the Epoch) of when the commit
   /// landed.
   @IntProperty(propertyName: 'CreateTimestamp', required: true)
diff --git a/app_dart/lib/src/model/appengine/task.dart b/app_dart/lib/src/model/appengine/task.dart
index cc4b48c..002f32f 100644
--- a/app_dart/lib/src/model/appengine/task.dart
+++ b/app_dart/lib/src/model/appengine/task.dart
@@ -6,6 +6,7 @@
 import 'package:json_annotation/json_annotation.dart';
 
 import '../../request_handling/exceptions.dart';
+import '../../service/datastore.dart';
 import '../../service/logging.dart';
 import '../ci_yaml/target.dart';
 import '../luci/push_message.dart';
@@ -70,6 +71,64 @@
     );
   }
 
+  /// Lookup [Task] from Datastore from its parent key and name.
+  static Future<Task> fromCommitKey({
+    required DatastoreService datastore,
+    required Key<String> commitKey,
+    required String name,
+  }) async {
+    if (name.isEmpty) {
+      throw const BadRequestException('task name is null');
+    }
+    final Query<Task> query = datastore.db.query<Task>(ancestorKey: commitKey)..filter('name =', name);
+    final List<Task> tasks = await query.run().toList();
+    if (tasks.length != 1) {
+      log.severe('Found ${tasks.length} entries for builder $name');
+      throw InternalServerError('Expected to find 1 task for $name, but found ${tasks.length}');
+    }
+    return tasks.single;
+  }
+
+  /// Lookup [Task] from its [key].
+  ///
+  /// This is the fastest way to lookup [Task], but requires [id] to be passed
+  /// as it is generated from Datastore.
+  static Future<Task> fromKey({
+    required DatastoreService datastore,
+    required Key<String> commitKey,
+    required int id,
+  }) {
+    log.fine('Looking up key...');
+    final Key<int> key = Key<int>(commitKey, Task, id);
+    return datastore.lookupByValue<Task>(key);
+  }
+
+  /// Lookup [Task] from Datastore.
+  ///
+  /// Either name or id must be given to lookup [Task].
+  ///
+  /// Prefer passing [id] when possible as it is a faster lookup.
+  static Future<Task> fromDatastore({
+    required DatastoreService datastore,
+    required Key<String> commitKey,
+    String? name,
+    String? id,
+  }) {
+    if (id == null) {
+      return Task.fromCommitKey(
+        datastore: datastore,
+        commitKey: commitKey,
+        name: name!,
+      );
+    }
+
+    return Task.fromKey(
+      datastore: datastore,
+      commitKey: commitKey,
+      id: int.parse(id),
+    );
+  }
+
   /// The task was cancelled.
   static const String statusCancelled = 'Cancelled';
 
diff --git a/app_dart/lib/src/model/gerrit/commit.dart b/app_dart/lib/src/model/gerrit/commit.dart
index 8044ec8..e5b7cc7 100644
--- a/app_dart/lib/src/model/gerrit/commit.dart
+++ b/app_dart/lib/src/model/gerrit/commit.dart
@@ -20,7 +20,7 @@
     this.commit,
     this.tree,
     this.author,
-    this.comitter,
+    this.committer,
     this.message,
   });
 
@@ -29,7 +29,7 @@
   final String? commit;
   final String? tree;
   final GerritUser? author;
-  final GerritUser? comitter;
+  final GerritUser? committer;
   final String? message;
 
   @override
diff --git a/app_dart/lib/src/model/gerrit/commit.g.dart b/app_dart/lib/src/model/gerrit/commit.g.dart
index a25363c..aaec6bd 100644
--- a/app_dart/lib/src/model/gerrit/commit.g.dart
+++ b/app_dart/lib/src/model/gerrit/commit.g.dart
@@ -12,7 +12,7 @@
       commit: json['commit'] as String?,
       tree: json['tree'] as String?,
       author: json['author'] == null ? null : GerritUser.fromJson(json['author'] as Map<String, dynamic>),
-      comitter: json['comitter'] == null ? null : GerritUser.fromJson(json['comitter'] as Map<String, dynamic>),
+      committer: json['committer'] == null ? null : GerritUser.fromJson(json['committer'] as Map<String, dynamic>),
       message: json['message'] as String?,
     );
 
@@ -20,7 +20,7 @@
       'commit': instance.commit,
       'tree': instance.tree,
       'author': instance.author,
-      'comitter': instance.comitter,
+      'committer': instance.committer,
       'message': instance.message,
     };
 
diff --git a/app_dart/lib/src/model/luci/buildbucket.dart b/app_dart/lib/src/model/luci/buildbucket.dart
index 88bebad..903639e 100644
--- a/app_dart/lib/src/model/luci/buildbucket.dart
+++ b/app_dart/lib/src/model/luci/buildbucket.dart
@@ -591,7 +591,7 @@
   /// * ["blamelist""]
   /// * ["$recipe_engine/runtime", "is_luci"]
   /// * ["$recipe_engine/runtime", "is_experimental"]
-  final Map<String, dynamic>? properties;
+  final Map<String, Object>? properties;
 
   /// The value for Build.input.gitiles_commit.
   ///
@@ -809,7 +809,7 @@
   static Input fromJson(Map<String, dynamic> json) => _$InputFromJson(json);
 
   /// The build properties of a build.
-  final Map<String, dynamic>? properties;
+  final Map<String, Object>? properties;
 
   /// The [GitilesCommit] information for a build.
   final GitilesCommit? gitilesCommit;
diff --git a/app_dart/lib/src/model/luci/buildbucket.g.dart b/app_dart/lib/src/model/luci/buildbucket.g.dart
index 06683d7..6cb274c 100644
--- a/app_dart/lib/src/model/luci/buildbucket.g.dart
+++ b/app_dart/lib/src/model/luci/buildbucket.g.dart
@@ -327,7 +327,9 @@
       experimental: $enumDecodeNullable(_$TrinaryEnumMap, json['experimental']),
       gitilesCommit:
           json['gitilesCommit'] == null ? null : GitilesCommit.fromJson(json['gitilesCommit'] as Map<String, dynamic>),
-      properties: json['properties'] as Map<String, dynamic>?,
+      properties: (json['properties'] as Map<String, dynamic>?)?.map(
+        (k, e) => MapEntry(k, e as Object),
+      ),
       dimensions: (json['dimensions'] as List<dynamic>?)
           ?.map((e) => RequestedDimension.fromJson(e as Map<String, dynamic>))
           .toList(),
@@ -461,7 +463,9 @@
     value == null ? null : toJson(value);
 
 Input _$InputFromJson(Map<String, dynamic> json) => Input(
-      properties: json['properties'] as Map<String, dynamic>?,
+      properties: (json['properties'] as Map<String, dynamic>?)?.map(
+        (k, e) => MapEntry(k, e as Object),
+      ),
       gitilesCommit:
           json['gitilesCommit'] == null ? null : GitilesCommit.fromJson(json['gitilesCommit'] as Map<String, dynamic>),
       experimental: json['experimental'] as bool?,
diff --git a/app_dart/lib/src/request_handlers/reset_prod_task.dart b/app_dart/lib/src/request_handlers/reset_prod_task.dart
index 6a7b9cd..85c3e40 100644
--- a/app_dart/lib/src/request_handlers/reset_prod_task.dart
+++ b/app_dart/lib/src/request_handlers/reset_prod_task.dart
@@ -19,7 +19,6 @@
 import '../request_handling/exceptions.dart';
 import '../service/config.dart';
 import '../service/datastore.dart';
-import '../service/logging.dart';
 import '../service/luci_build_service.dart';
 import '../service/scheduler.dart';
 
@@ -119,50 +118,17 @@
       final Key<int> key = config.keyHelper.decode(encodedKey) as Key<int>;
       return datastore.lookupByValue<Task>(key);
     }
-
-    final Key<String> commitKey = await _constructCommitKey(
-      datastore: datastore,
+    final Key<String> commitKey = Commit.createKey(
+      db: datastore.db,
+      slug: slug!,
       gitBranch: gitBranch!,
       sha: sha!,
-      slug: slug!,
     );
-
-    final Query<Task> query = datastore.db.query<Task>(ancestorKey: commitKey);
-    final List<Task> initialTasks = await query.run().toList();
-    log.fine('Found ${initialTasks.length} tasks for commit');
-    final List<Task> tasks = <Task>[];
-    log.fine('Searching for task with name=$name');
-    for (Task task in initialTasks) {
-      if (task.name == name) {
-        tasks.add(task);
-      }
-    }
-
-    if (tasks.length != 1) {
-      log.severe('Found ${tasks.length} entries for builder $name');
-      throw InternalServerError('Expected to find 1 task for $name, but found ${tasks.length}');
-    }
-
-    return tasks.single;
-  }
-
-  /// Construct the Datastore key for [Commit] that is the ancestor to this [Task].
-  ///
-  /// Throws [BadRequestException] if the given git branch does not exist in [CocoonConfig].
-  Future<Key<String>> _constructCommitKey({
-    required DatastoreService datastore,
-    required String gitBranch,
-    required String sha,
-    required RepositorySlug slug,
-  }) async {
-    gitBranch = gitBranch.trim();
-    sha = sha.trim();
-    final String id = '${slug.fullName}/$gitBranch/$sha';
-    final Key<String> commitKey = datastore.db.emptyKey.append<String>(Commit, id: id);
-    log.fine('Constructed commit key=$id');
-    // Return the official key from Datastore for task lookups.
-    final Commit commit = await datastore.lookupByValue<Commit>(commitKey);
-    return commit.key;
+    return Task.fromDatastore(
+      datastore: datastore,
+      commitKey: commitKey,
+      name: name!,
+    );
   }
 
   /// Returns the [Commit] associated with [Task].
diff --git a/app_dart/lib/src/service/luci_build_service.dart b/app_dart/lib/src/service/luci_build_service.dart
index a67e7b5..b1526a8 100644
--- a/app_dart/lib/src/service/luci_build_service.dart
+++ b/app_dart/lib/src/service/luci_build_service.dart
@@ -362,10 +362,10 @@
     );
   }
 
-  /// Sends [ScheduleBuildRequest] for [pullRequest] using [checkRunEvent].
+  /// Sends presubmit [ScheduleBuildRequest] for a pull request using [checkRunEvent].
   ///
   /// Returns the [Build] returned by scheduleBuildRequest.
-  Future<Build> rescheduleUsingCheckRunEvent(cocoon_checks.CheckRunEvent checkRunEvent) async {
+  Future<Build> reschedulePresubmitBuildUsingCheckRunEvent(cocoon_checks.CheckRunEvent checkRunEvent) async {
     final github.RepositorySlug slug = checkRunEvent.repository!.slug();
 
     final String sha = checkRunEvent.checkRun!.headSha!;
@@ -379,36 +379,62 @@
     );
 
     final Iterable<Build> builds = await getTryBuilds(slug, sha, checkName);
-
-    if (builds.isNotEmpty) {
-      final Build build = builds.first;
-
-      final String prString = build.tags!['buildset']!.firstWhere((String? element) => element!.startsWith('pr/git/'))!;
-      final String cipdVersion = build.tags!['cipd_version']![0]!;
-      final int prNumber = int.parse(prString.split('/')[2]);
-
-      final Map<String, dynamic> userData = <String, dynamic>{'check_run_id': githubCheckRun.id};
-      final Map<String, dynamic>? properties = build.input!.properties;
-      log.info('input ${build.input!} properties $properties');
-
-      final ScheduleBuildRequest scheduleBuildRequest = _createPresubmitScheduleBuild(
-        slug: slug,
-        sha: sha,
-        checkName: checkName,
-        pullRequestNumber: prNumber,
-        cipdVersion: cipdVersion,
-        properties: properties,
-        userData: userData,
-      );
-
-      final Build scheduleBuild = await buildBucketClient.scheduleBuild(scheduleBuildRequest);
-
-      final String buildUrl = 'https://ci.chromium.org/ui/b/${scheduleBuild.id}';
-      await githubChecksUtil.updateCheckRun(config, slug, githubCheckRun, detailsUrl: buildUrl);
-      return scheduleBuild;
-    } else {
+    if (builds.isEmpty) {
       throw NoBuildFoundException('Unable to find try build.');
     }
+
+    final Build build = builds.first;
+    final String prString = build.tags!['buildset']!.firstWhere((String? element) => element!.startsWith('pr/git/'))!;
+    final String cipdVersion = build.tags!['cipd_version']![0]!;
+    final int prNumber = int.parse(prString.split('/')[2]);
+
+    final Map<String, dynamic> userData = <String, dynamic>{'check_run_id': githubCheckRun.id};
+    final Map<String, Object>? properties = build.input!.properties;
+    log.info('input ${build.input!} properties $properties');
+
+    final ScheduleBuildRequest scheduleBuildRequest = _createPresubmitScheduleBuild(
+      slug: slug,
+      sha: sha,
+      checkName: checkName,
+      pullRequestNumber: prNumber,
+      cipdVersion: cipdVersion,
+      properties: properties,
+      userData: userData,
+    );
+
+    final Build scheduleBuild = await buildBucketClient.scheduleBuild(scheduleBuildRequest);
+
+    final String buildUrl = 'https://ci.chromium.org/ui/b/${scheduleBuild.id}';
+    await githubChecksUtil.updateCheckRun(config, slug, githubCheckRun, detailsUrl: buildUrl);
+    return scheduleBuild;
+  }
+
+  /// Sends postsubmit [ScheduleBuildRequest] for a commit using [checkRunEvent], [Commit], [Task], and [Target].
+  ///
+  /// Returns the [Build] returned by scheduleBuildRequest.
+  Future<Build> reschedulePostsubmitBuildUsingCheckRunEvent(
+    cocoon_checks.CheckRunEvent checkRunEvent, {
+    required Commit commit,
+    required Task task,
+    required Target target,
+  }) async {
+    final github.RepositorySlug slug = checkRunEvent.repository!.slug();
+    final String sha = checkRunEvent.checkRun!.headSha!;
+    final String checkName = checkRunEvent.checkRun!.name!;
+
+    final Iterable<Build> builds = await getProdBuilds(slug, sha, checkName);
+    if (builds.isEmpty) {
+      throw NoBuildFoundException('Unable to find prod build.');
+    }
+
+    final Build build = builds.first;
+    final Map<String, Object>? properties = build.input!.properties;
+    log.info('input ${build.input!} properties $properties');
+
+    final ScheduleBuildRequest scheduleBuildRequest =
+        await _createPostsubmitScheduleBuild(commit: commit, target: target, task: task, properties: properties);
+    final Build scheduleBuild = await buildBucketClient.scheduleBuild(scheduleBuildRequest);
+    return scheduleBuild;
   }
 
   /// Gets [Build] using its [id] and passing the additional
@@ -474,15 +500,15 @@
     required String checkName,
     required int pullRequestNumber,
     required String cipdVersion,
-    Map<String, dynamic>? properties,
+    Map<String, Object>? properties,
     Map<String, List<String>>? tags,
     Map<String, dynamic>? userData,
     List<RequestedDimension>? dimensions,
   }) {
-    final Map<String, dynamic> processedProperties = <String, dynamic>{};
-    processedProperties.addAll(properties ?? <String, dynamic>{});
+    final Map<String, Object> processedProperties = <String, Object>{};
+    processedProperties.addAll(properties ?? <String, Object>{});
     processedProperties.addEntries(
-      <String, dynamic>{
+      <String, Object>{
         'git_url': 'https://github.com/${slug.owner}/${slug.name}',
         'git_ref': 'refs/pull/$pullRequestNumber/head',
         'exe_cipd_version': cipdVersion,
diff --git a/app_dart/lib/src/service/scheduler.dart b/app_dart/lib/src/service/scheduler.dart
index 64365de..e52bbc1 100644
--- a/app_dart/lib/src/service/scheduler.dart
+++ b/app_dart/lib/src/service/scheduler.dart
@@ -455,7 +455,7 @@
         final String? name = checkRunEvent.checkRun!.name;
         bool success = false;
         if (name == kCiYamlCheckName) {
-          // The [CheckRunEvent.checkRun.pullRequests] array is empty for this
+          // The CheckRunEvent.checkRun.pullRequests array is empty for this
           // event, so we need to find the matching pull request.
           final RepositorySlug slug = checkRunEvent.repository!.slug();
           final String headSha = checkRunEvent.checkRun!.headSha!;
@@ -471,7 +471,42 @@
           }
         } else {
           try {
-            await luciBuildService.rescheduleUsingCheckRunEvent(checkRunEvent);
+            final String sha = checkRunEvent.checkRun!.headSha!;
+            final String checkName = checkRunEvent.checkRun!.name!;
+            final RepositorySlug slug = checkRunEvent.repository!.slug();
+
+            // TODO(nehalvpatel): Use head_branch from checkRunEvent.checkRun.checkSuite, https://github.com/flutter/flutter/issues/119171
+            final String gitBranch = Config.defaultBranch(slug);
+
+            // Only merged commits are added to the datastore. If a matching commit is found, this must be a postsubmit checkrun.
+            datastore = datastoreProvider(config.db);
+            final Key<String> commitKey =
+                Commit.createKey(db: datastore.db, slug: slug, gitBranch: gitBranch, sha: sha);
+            Commit? commit;
+            try {
+              commit = await Commit.fromDatastore(datastore: datastore, key: commitKey);
+              log.fine('Commit found in datastore.');
+            } on KeyNotFoundException {
+              log.fine('Commit not found in datastore.');
+            }
+
+            if (commit == null) {
+              log.fine('Rescheduling presubmit build.');
+              await luciBuildService.reschedulePresubmitBuildUsingCheckRunEvent(checkRunEvent);
+            } else {
+              log.fine('Rescheduling postsubmit build.');
+              final Task task = await Task.fromDatastore(datastore: datastore, commitKey: commitKey, name: checkName);
+              final CiYaml ciYaml = await getCiYaml(commit);
+              final Target target =
+                  ciYaml.postsubmitTargets.singleWhere((Target target) => target.value.name == task.name);
+              await luciBuildService.reschedulePostsubmitBuildUsingCheckRunEvent(
+                checkRunEvent,
+                commit: commit,
+                task: task,
+                target: target,
+              );
+            }
+
             success = true;
           } on NoBuildFoundException {
             log.warning('No build found to reschedule.');
diff --git a/app_dart/test/model/commit_test.dart b/app_dart/test/model/commit_test.dart
new file mode 100644
index 0000000..3907e77
--- /dev/null
+++ b/app_dart/test/model/commit_test.dart
@@ -0,0 +1,61 @@
+// Copyright 2023 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:cocoon_service/src/model/appengine/commit.dart';
+import 'package:cocoon_service/src/service/datastore.dart';
+import 'package:gcloud/db.dart';
+import 'package:github/github.dart';
+import 'package:test/test.dart';
+
+import '../src/datastore/fake_config.dart';
+import '../src/datastore/fake_datastore.dart';
+import '../src/utilities/entity_generators.dart';
+
+void main() {
+  group('Commit.composeKey', () {
+    test('creates valid key', () {
+      final FakeDatastoreDB db = FakeDatastoreDB();
+      final RepositorySlug slug = RepositorySlug('flutter', 'flutter');
+      const String gitBranch = 'main';
+      const String sha = 'abc';
+      final key = Commit.createKey(db: db, slug: slug, gitBranch: gitBranch, sha: sha);
+      expect(key.id, equals('flutter/flutter/main/abc'));
+    });
+  });
+
+  group('Commit.fromDatastore', () {
+    late FakeConfig config;
+    late Commit expectedCommit;
+
+    setUp(() {
+      config = FakeConfig();
+      expectedCommit = generateCommit(1);
+      config.db.values[expectedCommit.key] = expectedCommit;
+    });
+
+    test('look up by id', () async {
+      final Commit commit = await Commit.fromDatastore(
+        datastore: DatastoreService(config.db, 5),
+        key: expectedCommit.key,
+      );
+      expect(commit, expectedCommit);
+    });
+
+    test('look up by id fails if cannot be found', () async {
+      final datastore = DatastoreService(config.db, 5);
+      expect(
+        Commit.fromDatastore(
+          datastore: datastore,
+          key: Commit.createKey(
+            db: datastore.db,
+            slug: RepositorySlug('abc', 'test'),
+            gitBranch: 'main',
+            sha: 'def',
+          ),
+        ),
+        throwsA(isA<KeyNotFoundException>()),
+      );
+    });
+  });
+}
diff --git a/app_dart/test/model/task_test.dart b/app_dart/test/model/task_test.dart
index 87381b8..b2e9d3f 100644
--- a/app_dart/test/model/task_test.dart
+++ b/app_dart/test/model/task_test.dart
@@ -2,11 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'package:cocoon_service/src/model/appengine/commit.dart';
 import 'package:cocoon_service/src/model/appengine/task.dart';
 import 'package:cocoon_service/src/model/luci/push_message.dart';
+import 'package:cocoon_service/src/request_handling/exceptions.dart';
+import 'package:cocoon_service/src/service/datastore.dart';
 import 'package:gcloud/db.dart';
 import 'package:test/test.dart';
 
+import '../src/datastore/fake_config.dart';
 import '../src/utilities/entity_generators.dart';
 
 void main() {
@@ -174,9 +178,89 @@
       });
     });
   });
-}
 
-void validateModel(Task task) {
-  // Throws an exception when property validation fails.
-  ModelDBImpl().toDatastoreEntity(task);
+  // TODO(chillers): There is a bug where `dart test` does not work in offline mode.
+  // Need to file issue and get traces.
+  group('Task.fromDatastore', () {
+    late FakeConfig config;
+    late Commit commit;
+    late Task expectedTask;
+
+    setUp(() {
+      config = FakeConfig();
+      commit = generateCommit(1);
+      expectedTask = generateTask(1, parent: commit);
+      config.db.values[commit.key] = commit;
+      config.db.values[expectedTask.key] = expectedTask;
+    });
+
+    test('look up by id', () async {
+      final Task task = await Task.fromDatastore(
+        datastore: DatastoreService(config.db, 5),
+        commitKey: commit.key,
+        id: '${expectedTask.id}',
+      );
+      expect(task, expectedTask);
+    });
+
+    test('look up by id fails if cannot be found', () async {
+      expect(
+        Task.fromDatastore(
+          datastore: DatastoreService(config.db, 5),
+          commitKey: commit.key,
+          id: '12345',
+        ),
+        throwsA(isA<KeyNotFoundException>()),
+      );
+    });
+
+    test('look up by name', () async {
+      final Task task = await Task.fromDatastore(
+        datastore: DatastoreService(config.db, 5),
+        commitKey: commit.key,
+        name: expectedTask.name,
+      );
+      expect(task, expectedTask);
+    });
+
+    test('look up by name fails if cannot be found', () async {
+      try {
+        await Task.fromDatastore(
+          datastore: DatastoreService(config.db, 5),
+          commitKey: commit.key,
+          name: 'Linux not_found',
+        );
+      } catch (e) {
+        expect(e, isA<InternalServerError>());
+        expect(
+          e.toString(),
+          equals(
+            'HTTP 500: Expected to find 1 task for Linux not_found, but found 0',
+          ),
+        );
+      }
+    });
+
+    test('look up by name fails if multiple Tasks with the same name are found', () async {
+      final DatastoreService datastore = DatastoreService(config.db, 5);
+      final String taskName = expectedTask.name!;
+      final Task duplicatedTask = generateTask(2, parent: commit, name: taskName);
+      config.db.values[duplicatedTask.key] = duplicatedTask;
+      try {
+        await Task.fromDatastore(
+          datastore: datastore,
+          commitKey: commit.key,
+          name: taskName,
+        );
+      } catch (e) {
+        expect(e, isA<InternalServerError>());
+        expect(
+          e.toString(),
+          equals(
+            'HTTP 500: Expected to find 1 task for $taskName, but found 2',
+          ),
+        );
+      }
+    });
+  });
 }
diff --git a/app_dart/test/service/gerrit_service_test.dart b/app_dart/test/service/gerrit_service_test.dart
index 80edcfd..cc94816 100644
--- a/app_dart/test/service/gerrit_service_test.dart
+++ b/app_dart/test/service/gerrit_service_test.dart
@@ -74,6 +74,9 @@
       expect(commit.author?.email, 'dash@flutter.dev');
       expect(commit.author?.name, 'Dash');
       expect(commit.author?.time, isNotNull);
+      expect(commit.committer?.email, 'flutter-scoped@luci-project-accounts.iam.gserviceaccount.com');
+      expect(commit.committer?.name, 'CQ Bot Account');
+      expect(commit.committer?.time, isNotNull);
       final DateTime time = commit.author!.time!;
       final DateTime expectedTime = DateTime.utc(2022, 7, 12, 17, 21, 25);
       expect(time, expectedTime);
diff --git a/app_dart/test/service/luci_build_service_test.dart b/app_dart/test/service/luci_build_service_test.dart
index af50931..19a6459 100644
--- a/app_dart/test/service/luci_build_service_test.dart
+++ b/app_dart/test/service/luci_build_service_test.dart
@@ -557,8 +557,15 @@
       final Map<String, dynamic> jsonSubMap = json.decode(jsonMap['2']);
       final cocoon_checks.CheckRunEvent checkRunEvent = cocoon_checks.CheckRunEvent.fromJson(jsonSubMap);
 
-      expect(() async => await service.rescheduleUsingCheckRunEvent(checkRunEvent),
-          throwsA(const TypeMatcher<NoBuildFoundException>()));
+      expect(
+        () async => await service.reschedulePostsubmitBuildUsingCheckRunEvent(
+          checkRunEvent,
+          commit: generateCommit(0),
+          task: generateTask(0),
+          target: generateTarget(0),
+        ),
+        throwsA(const TypeMatcher<NoBuildFoundException>()),
+      );
     });
 
     test('do not create postsubmit checkrun for bringup: true target', () async {
diff --git a/app_dart/test/service/scheduler_test.dart b/app_dart/test/service/scheduler_test.dart
index 78c1054..807b7cb 100644
--- a/app_dart/test/service/scheduler_test.dart
+++ b/app_dart/test/service/scheduler_test.dart
@@ -32,6 +32,7 @@
 import '../src/datastore/fake_datastore.dart';
 import '../src/service/fake_build_status_provider.dart';
 import '../src/request_handling/fake_pubsub.dart';
+import '../src/service/fake_buildbucket.dart';
 import '../src/service/fake_gerrit_service.dart';
 import '../src/service/fake_github_service.dart';
 import '../src/service/fake_luci_build_service.dart';
@@ -450,18 +451,105 @@
         verify(mockGithubChecksUtil.createCheckRun(any, any, any, any)).called(1);
       });
 
-      test('rerequested triggers a single luci build', () async {
-        when(mockGithubChecksUtil.createCheckRun(any, any, any, any)).thenAnswer((_) async {
-          return CheckRun.fromJson(const <String, dynamic>{
-            'id': 1,
-            'started_at': '2020-05-10T02:49:31Z',
-            'check_suite': <String, dynamic>{'id': 2},
-          });
+      test('rerequested presubmit check triggers presubmit build', () async {
+        // Note that we're not inserting any commits into the db, because
+        // only postsubmit commits are stored in the datastore.
+        config = FakeConfig(dbValue: db);
+        db = FakeDatastoreDB();
+
+        // Set up mock buildbucket to validate which bucket is requested.
+        final MockBuildBucketClient mockBuildbucket = MockBuildBucketClient();
+        when(mockBuildbucket.batch(any)).thenAnswer((i) async {
+          return FakeBuildBucketClient().batch(i.positionalArguments[0]);
         });
+        when(mockBuildbucket.scheduleBuild(any, buildBucketUri: anyNamed('buildBucketUri')))
+            .thenAnswer((realInvocation) async {
+          final ScheduleBuildRequest scheduleBuildRequest = realInvocation.positionalArguments[0];
+          // Ensure this is an attempt to schedule a presubmit build by
+          // verifying that bucket == 'try'.
+          expect(scheduleBuildRequest.builderId.bucket, equals('try'));
+          return const Build(builderId: BuilderId(), id: '');
+        });
+
+        scheduler = Scheduler(
+          cache: cache,
+          config: config,
+          githubChecksService: GithubChecksService(config, githubChecksUtil: mockGithubChecksUtil),
+          luciBuildService: FakeLuciBuildService(
+            config: config,
+            githubChecksUtil: mockGithubChecksUtil,
+            buildbucket: mockBuildbucket,
+          ),
+        );
         final cocoon_checks.CheckRunEvent checkRunEvent = cocoon_checks.CheckRunEvent.fromJson(
           jsonDecode(checkRunString) as Map<String, dynamic>,
         );
         expect(await scheduler.processCheckRun(checkRunEvent), true);
+        verify(mockBuildbucket.scheduleBuild(any, buildBucketUri: anyNamed('buildBucketUri'))).called(1);
+        verify(mockGithubChecksUtil.createCheckRun(any, any, any, any)).called(1);
+      });
+
+      test('rerequested postsubmit check triggers postsubmit build', () async {
+        // Set up datastore with postsubmit entities matching [checkRunString].
+        db = FakeDatastoreDB();
+        config = FakeConfig(dbValue: db, postsubmitSupportedReposValue: {RepositorySlug('abc', 'cocoon')});
+        final Commit commit = generateCommit(
+          1,
+          sha: '66d6bd9a3f79a36fe4f5178ccefbc781488a596c',
+          branch: 'master',
+          owner: 'abc',
+          repo: 'cocoon',
+        );
+        config.db.values[commit.key] = commit;
+        final Task task = generateTask(1, name: "test1", parent: commit);
+        config.db.values[task.key] = task;
+
+        // Set up ci.yaml with task name from [checkRunString].
+        httpClient = MockClient((http.Request request) async {
+          if (request.url.path.contains('.ci.yaml')) {
+            return http.Response(
+              r'''
+enabled_branches:
+  - master
+targets:
+  - name: test1
+''',
+              200,
+            );
+          }
+          throw Exception('Failed to find ${request.url.path}');
+        });
+
+        // Set up mock buildbucket to validate which bucket is requested.
+        final MockBuildBucketClient mockBuildbucket = MockBuildBucketClient();
+        when(mockBuildbucket.batch(any)).thenAnswer((i) async {
+          return FakeBuildBucketClient().batch(i.positionalArguments[0]);
+        });
+        when(mockBuildbucket.scheduleBuild(any, buildBucketUri: anyNamed('buildBucketUri')))
+            .thenAnswer((realInvocation) async {
+          final ScheduleBuildRequest scheduleBuildRequest = realInvocation.positionalArguments[0];
+          // Ensure this is an attempt to schedule a postsubmit build by
+          // verifying that bucket == 'prod'.
+          expect(scheduleBuildRequest.builderId.bucket, equals('prod'));
+          return const Build(builderId: BuilderId(), id: '');
+        });
+
+        scheduler = Scheduler(
+          cache: cache,
+          config: config,
+          githubChecksService: GithubChecksService(config, githubChecksUtil: mockGithubChecksUtil),
+          httpClientProvider: () => httpClient,
+          luciBuildService: FakeLuciBuildService(
+            config: config,
+            githubChecksUtil: mockGithubChecksUtil,
+            buildbucket: mockBuildbucket,
+          ),
+        );
+        final cocoon_checks.CheckRunEvent checkRunEvent = cocoon_checks.CheckRunEvent.fromJson(
+          jsonDecode(checkRunString) as Map<String, dynamic>,
+        );
+        expect(await scheduler.processCheckRun(checkRunEvent), true);
+        verify(mockBuildbucket.scheduleBuild(any, buildBucketUri: anyNamed('buildBucketUri'))).called(1);
         verify(mockGithubChecksUtil.createCheckRun(any, any, any, any)).called(1);
       });
 
diff --git a/app_dart/test/src/datastore/fake_config.dart b/app_dart/test/src/datastore/fake_config.dart
index 7233616..057a31c 100644
--- a/app_dart/test/src/datastore/fake_config.dart
+++ b/app_dart/test/src/datastore/fake_config.dart
@@ -234,10 +234,7 @@
 
   @override
   bool githubPostsubmitSupportedRepo(gh.RepositorySlug slug) {
-    return <gh.RepositorySlug>[
-      Config.packagesSlug,
-      Config.pluginsSlug,
-    ].contains(slug);
+    return postsubmitSupportedRepos.contains(slug);
   }
 
   @override
@@ -279,7 +276,7 @@
 
   @override
   Set<gh.RepositorySlug> get postsubmitSupportedRepos =>
-      postsubmitSupportedReposValue ?? <gh.RepositorySlug>{Config.packagesSlug};
+      postsubmitSupportedReposValue ?? <gh.RepositorySlug>{Config.packagesSlug, Config.pluginsSlug};
 
   @override
   Future<Iterable<Branch>> getBranches(gh.RepositorySlug slug) async {
diff --git a/app_dart/test/src/datastore/fake_datastore.dart b/app_dart/test/src/datastore/fake_datastore.dart
index 3b961ae..f749dd4 100644
--- a/app_dart/test/src/datastore/fake_datastore.dart
+++ b/app_dart/test/src/datastore/fake_datastore.dart
@@ -144,8 +144,8 @@
 /// A query that will return all values of type `T` that exist in the
 /// [FakeDatastoreDB.values] map.
 ///
-/// This fake query ignores any [filter] or [order] directives, though it does
-/// respect [limit] and [offset] directives.
+/// This fake query respects [order], [limit], and [offset]. However, [filter]
+/// may require local additions here to respect new filters.
 class FakeQuery<T extends Model<dynamic>> implements Query<T> {
   FakeQuery._(this.db, this.results);
 
@@ -189,14 +189,14 @@
   Stream<T> run() {
     Iterable<T> resultsView = results;
 
-    // This considers only the special case when there exists [branch] or [pr] filter.
     for (FakeFilterSpec filter in filters) {
       final String filterString = filter.filterString;
       final Object? value = filter.comparisonObject;
       if (filterString.contains('branch =') ||
           filterString.contains('head =') ||
           filterString.contains('pr =') ||
-          filterString.contains('repository =')) {
+          filterString.contains('repository =') ||
+          filterString.contains('name =')) {
         resultsView = resultsView.where((T result) => result.toString().contains(value.toString()));
       }
     }
@@ -214,6 +214,9 @@
 
   final String filterString;
   final Object? comparisonObject;
+
+  @override
+  String toString() => 'FakeFilterSpec($filterString, $comparisonObject)';
 }
 
 class FakeOrderSpec {
diff --git a/app_dart/test/src/service/fake_buildbucket.dart b/app_dart/test/src/service/fake_buildbucket.dart
index b5b4bad..17ee23a 100644
--- a/app_dart/test/src/service/fake_buildbucket.dart
+++ b/app_dart/test/src/service/fake_buildbucket.dart
@@ -62,7 +62,7 @@
                     'cipd_version': <String>['refs/heads/main']
                   },
                   input: Input(
-                    properties: <String, dynamic>{'bringup': 'true'},
+                    properties: <String, Object>{'bringup': 'true'},
                   ),
                 ),
               ],
diff --git a/app_dart/test/src/utilities/entity_generators.dart b/app_dart/test/src/utilities/entity_generators.dart
index 383b24e..c3dba7e 100644
--- a/app_dart/test/src/utilities/entity_generators.dart
+++ b/app_dart/test/src/utilities/entity_generators.dart
@@ -15,23 +15,24 @@
 
 import '../service/fake_scheduler.dart';
 
-Key<T> generateKey<T>(Type type, T id) => Key<T>.emptyKey(Partition('flutter-dashboard')).append<T>(type, id: id);
+Key<T> generateKey<T>(Type type, T id) => Key<T>.emptyKey(Partition(null)).append<T>(type, id: id);
 
 Commit generateCommit(
   int i, {
   String? sha,
   String branch = 'master',
+  String? owner = 'flutter',
   String repo = 'flutter',
   int? timestamp,
 }) =>
     Commit(
       sha: sha ?? '$i',
       timestamp: timestamp ?? i,
-      repository: 'flutter/$repo',
+      repository: '$owner/$repo',
       branch: branch,
       key: generateKey<String>(
         Commit,
-        'flutter/$repo/$branch/${sha ?? '$i'}',
+        '$owner/$repo/$branch/${sha ?? '$i'}',
       ),
     );
 
diff --git a/app_dart/test/src/utilities/mocks.mocks.dart b/app_dart/test/src/utilities/mocks.mocks.dart
index 394960c..7f6ba5d 100644
--- a/app_dart/test/src/utilities/mocks.mocks.dart
+++ b/app_dart/test/src/utilities/mocks.mocks.dart
@@ -9,9 +9,9 @@
 import 'dart:typed_data' as _i27;
 
 import 'package:cocoon_service/src/foundation/github_checks_util.dart' as _i11;
-import 'package:cocoon_service/src/foundation/utils.dart' as _i35;
+import 'package:cocoon_service/src/foundation/utils.dart' as _i36;
 import 'package:cocoon_service/src/model/appengine/commit.dart' as _i34;
-import 'package:cocoon_service/src/model/appengine/task.dart' as _i36;
+import 'package:cocoon_service/src/model/appengine/task.dart' as _i35;
 import 'package:cocoon_service/src/model/ci_yaml/target.dart' as _i32;
 import 'package:cocoon_service/src/model/github/checks.dart' as _i33;
 import 'package:cocoon_service/src/model/luci/buildbucket.dart' as _i9;
@@ -4877,20 +4877,51 @@
         )),
       ) as _i17.Future<_i9.Build>);
   @override
-  _i17.Future<_i9.Build> rescheduleUsingCheckRunEvent(_i33.CheckRunEvent? checkRunEvent) => (super.noSuchMethod(
+  _i17.Future<_i9.Build> reschedulePresubmitBuildUsingCheckRunEvent(_i33.CheckRunEvent? checkRunEvent) =>
+      (super.noSuchMethod(
         Invocation.method(
-          #rescheduleUsingCheckRunEvent,
+          #reschedulePresubmitBuildUsingCheckRunEvent,
           [checkRunEvent],
         ),
         returnValue: _i17.Future<_i9.Build>.value(_FakeBuild_8(
           this,
           Invocation.method(
-            #rescheduleUsingCheckRunEvent,
+            #reschedulePresubmitBuildUsingCheckRunEvent,
             [checkRunEvent],
           ),
         )),
       ) as _i17.Future<_i9.Build>);
   @override
+  _i17.Future<_i9.Build> reschedulePostsubmitBuildUsingCheckRunEvent(
+    _i33.CheckRunEvent? checkRunEvent, {
+    required _i34.Commit? commit,
+    required _i35.Task? task,
+    required _i32.Target? target,
+  }) =>
+      (super.noSuchMethod(
+        Invocation.method(
+          #reschedulePostsubmitBuildUsingCheckRunEvent,
+          [checkRunEvent],
+          {
+            #commit: commit,
+            #task: task,
+            #target: target,
+          },
+        ),
+        returnValue: _i17.Future<_i9.Build>.value(_FakeBuild_8(
+          this,
+          Invocation.method(
+            #reschedulePostsubmitBuildUsingCheckRunEvent,
+            [checkRunEvent],
+            {
+              #commit: commit,
+              #task: task,
+              #target: target,
+            },
+          ),
+        )),
+      ) as _i17.Future<_i9.Build>);
+  @override
   _i17.Future<_i9.Build> getBuildById(
     String? id, {
     String? fields,
@@ -4929,7 +4960,7 @@
   @override
   _i17.Future<void> schedulePostsubmitBuilds({
     required _i34.Commit? commit,
-    required List<_i35.Tuple<_i32.Target, _i36.Task, int>>? toBeScheduled,
+    required List<_i36.Tuple<_i32.Target, _i35.Task, int>>? toBeScheduled,
   }) =>
       (super.noSuchMethod(
         Invocation.method(
@@ -4965,7 +4996,7 @@
   _i17.Future<bool> checkRerunBuilder({
     required _i34.Commit? commit,
     required _i32.Target? target,
-    required _i36.Task? task,
+    required _i35.Task? task,
     required _i37.DatastoreService? datastore,
     Map<String, List<String>>? tags,
     bool? ignoreChecks = false,
diff --git a/licenses/check_licenses.dart b/licenses/check_licenses.dart
index 3a9ae9c..5d0494d 100644
--- a/licenses/check_licenses.dart
+++ b/licenses/check_licenses.dart
@@ -32,7 +32,7 @@
 
 // TESTS
 String _generateLicense(String prefix) {
-  return '${prefix}Copyright (2014|2015|2016|2017|2018|2019|2020|2021|2022) The Flutter Authors. All rights reserved.\n'
+  return '${prefix}Copyright (2014|2015|2016|2017|2018|2019|2020|2021|2022|2023) The Flutter Authors. All rights reserved.\n'
       '${prefix}Use of this source code is governed by a BSD-style license that can be\n'
       '${prefix}found in the LICENSE file.';
 }