diff --git a/buildman/manager/ephemeral.py b/buildman/manager/ephemeral.py
index 48f83e83a..a2e178d17 100644
--- a/buildman/manager/ephemeral.py
+++ b/buildman/manager/ephemeral.py
@@ -41,7 +41,7 @@ class EtcdAction(object):
 
 BuildInfo = namedtuple('BuildInfo', ['component', 'build_job', 'execution_id', 'executor_name'])
 
-def createAsyncEtcdClient(worker_threads=1, **kwargs):
+def _create_async_etcd_client(worker_threads=1, **kwargs):
   client = etcd.Client(**kwargs)
   async_executor = ThreadPoolExecutor(worker_threads)
   return AsyncWrapper(client, executor=async_executor), async_executor
@@ -57,7 +57,7 @@ class EphemeralBuilderManager(BaseManager):
   }
 
   def __init__(self, *args, **kwargs):
-    self._etcd_client_creator = kwargs.pop('etcd_creator', createAsyncEtcdClient)
+    self._etcd_client_creator = kwargs.pop('etcd_creator', _create_async_etcd_client)
 
     super(EphemeralBuilderManager, self).__init__(*args, **kwargs)
 
@@ -153,30 +153,32 @@ class EphemeralBuilderManager(BaseManager):
     if etcd_result is None:
       return
 
-    if etcd_result.action == EtcdAction.EXPIRE:
-      # Handle the expiration
-      logger.debug('Builder expired, clean up the old build node')
-      job_metadata = json.loads(etcd_result._prev_node.value)
-      build_job = BuildJob(AttrDict(job_metadata['job_queue_item']))
-      build_info = self._build_uuid_to_info.get(build_job.build_uuid)
-      if build_info is None:
-        logger.error('Could not find build info for job %s under etcd expire with metadata: %s',
-                      build_job.build_uuid, job_metadata)
-        return
+    if etcd_result.action != EtcdAction.EXPIRE:
+      return
 
-      execution_id = build_info.execution_id
+    # Handle the expiration
+    logger.debug('Builder expired, clean up the old build node')
+    job_metadata = json.loads(etcd_result._prev_node.value)
+    build_job = BuildJob(AttrDict(job_metadata['job_queue_item']))
+    build_info = self._build_uuid_to_info.get(build_job.build_uuid)
+    if build_info is None:
+      logger.error('Could not find build info for job %s under etcd expire with metadata: %s',
+                    build_job.build_uuid, job_metadata)
+      return
 
-      # If we have not yet received a heartbeat, then the node failed to boot in some way. We mark
-      # the job as incomplete here.
-      if not job_metadata.get('had_heartbeat', True):
-        logger.warning('Build executor failed to successfully boot with execution id %s',
-                       execution_id)
-        self.job_complete_callback(build_job, BuildJobResult.INCOMPLETE)
+    execution_id = build_info.execution_id
 
-      # Finally, we terminate the build execution for the job.
-      logger.info('Terminating expired build executor for job %s with execution id %s',
-                  build_job.build_uuid, execution_id)
-      yield From(self.kill_builder_executor(build_job.build_uuid))
+    # If we have not yet received a heartbeat, then the node failed to boot in some way. We mark
+    # the job as incomplete here.
+    if not job_metadata.get('had_heartbeat', True):
+      logger.warning('Build executor failed to successfully boot with execution id %s',
+                     execution_id)
+      self.job_complete_callback(build_job, BuildJobResult.INCOMPLETE)
+
+    # Finally, we terminate the build execution for the job.
+    logger.info('Terminating expired build executor for job %s with execution id %s',
+                build_job.build_uuid, execution_id)
+    yield From(self.kill_builder_executor(build_job.build_uuid))
 
   def _handle_realm_change(self, etcd_result):
     if etcd_result is None:
@@ -215,8 +217,10 @@ class EphemeralBuilderManager(BaseManager):
 
     # Create the build information block for the registered realm.
     build_job = BuildJob(AttrDict(realm_spec['job_queue_item']))
-    execution_id = realm_spec['execution_id']
-    executor_name = realm_spec['executor_name']
+
+    # TODO(jschorr): Remove the back-compat lookups once we've finished the rollout.
+    execution_id = realm_spec.get('execution_id', realm_spec.get('builder_id', None))
+    executor_name = realm_spec.get('executor_name', 'EC2Executor')
 
     build_info = BuildInfo(component=component, build_job=build_job, execution_id=execution_id,
                            executor_name=executor_name)
@@ -433,6 +437,9 @@ class EphemeralBuilderManager(BaseManager):
       'execution_id': execution_id,
       'executor_name': started_with_executor.name,
       'job_queue_item': build_job.job_item,
+
+      # TODO: remove this back-compat field once we finish the rollout.
+      'builder_id': execution_id,
     })
 
     try: