diff --git a/hyrex/dispatcher/sqlc/set_orphaned_task_execution_to_lost_and_retry.py b/hyrex/dispatcher/sqlc/set_orphaned_task_execution_to_lost_and_retry.py
index 6c05533..c51af0b 100644
--- a/hyrex/dispatcher/sqlc/set_orphaned_task_execution_to_lost_and_retry.py
+++ b/hyrex/dispatcher/sqlc/set_orphaned_task_execution_to_lost_and_retry.py
@@ -64,6 +64,7 @@
     NOW()
 FROM lost_tasks
 WHERE attempt_number < max_retries
+ON CONFLICT (task_name, idempotency_key) WHERE idempotency_key IS NOT NULL DO NOTHING
 """
 
 
diff --git a/hyrex/worker/executor/time_series_averager.py b/hyrex/worker/executor/time_series_averager.py
index b7b5411..1f5c681 100644
--- a/hyrex/worker/executor/time_series_averager.py
+++ b/hyrex/worker/executor/time_series_averager.py
@@ -1,4 +1,5 @@
 import time
+from collections import deque
 
 from pydantic import BaseModel
 
@@ -13,9 +14,17 @@ class MinuteAverage(BaseModel):
     average: float
 
 
+# Bound the per-averager ring buffer. The executor poll loop submits to these
+# averagers on every iteration and previously never pruned, which leaked ~40
+# MB/min per worker under an idle busy-poll. 10k entries is enough to hold
+# several minutes of stats at realistic submit rates while capping worst-case
+# memory at ~2 MB per averager.
+_MAX_DATA_POINTS = 10_000
+
+
 class TimeSeriesAverager:
     def __init__(self):
-        self.data_points: list[DataPoint] = []
+        self.data_points: deque[DataPoint] = deque(maxlen=_MAX_DATA_POINTS)
 
     def _get_minute_timestamp(self, timestamp: int) -> int:
         # Round down to nearest minute
@@ -71,9 +80,10 @@ def get_current_minute_average(self) -> MinuteAverage:
         return result
 
     def clear(self) -> None:
-        self.data_points = []
+        self.data_points.clear()
 
     def prune_data_older_than(self, timestamp: int) -> None:
-        self.data_points = [
-            point for point in self.data_points if point.timestamp >= timestamp
-        ]
+        self.data_points = deque(
+            (point for point in self.data_points if point.timestamp >= timestamp),
+            maxlen=_MAX_DATA_POINTS,
+        )
diff --git a/hyrex/worker/root_process.py b/hyrex/worker/root_process.py
index e9bb81e..be6cb04 100644
--- a/hyrex/worker/root_process.py
+++ b/hyrex/worker/root_process.py
@@ -227,7 +227,9 @@ def send_heartbeats(self):
         )
 
     def run(self):
-        self.message_listener_thread = threading.Thread(target=self._message_listener)
+        self.message_listener_thread = threading.Thread(
+            target=self._message_listener, daemon=True
+        )
         self.message_listener_thread.start()
         self.logger.info("Incoming message queue now active...")
 
@@ -332,8 +334,7 @@ def stop(self):
             self.message_listener_thread.join(timeout=5.0)
             if self.message_listener_thread.is_alive():
                 self.logger.warning("Message listener thread did not exit cleanly within timeout.")
-                # Force terminate the thread by setting it as daemon and exiting
-                # Python will clean it up on process exit
+                # Thread is a daemon, so the interpreter will terminate it on process exit.
             else:
                 self.logger.info("Message listener thread closed successfully.")