diff --git a/apps/api/src/services/platform_runtime.py b/apps/api/src/services/platform_runtime.py
index 9b5df8096..b999db320 100644
--- a/apps/api/src/services/platform_runtime.py
+++ b/apps/api/src/services/platform_runtime.py
@@ -19,7 +19,7 @@ from __future__ import annotations
 
 import hashlib
 import json
-from datetime import datetime, timedelta, timezone
+from datetime import UTC, datetime, timedelta
 from typing import Any
 from uuid import UUID
 
@@ -32,7 +32,7 @@ from src.db.awooop_models import (
     AwoooPRunStepJournal,
 )
 from src.db.base import get_db_context
-from src.services.run_state_machine import LEASE_TTL_SECONDS, transition
+from src.services.run_state_machine import transition
 from src.services.runtime_correlation import (
     canonical_traceparent,
     correlation_readback_for_run,
@@ -205,7 +205,7 @@ async def create_run(
     trace_id = correlation.trace_id
     # AwoooPRunState timestamps use PostgreSQL TIMESTAMP WITHOUT TIME ZONE.
     # Normalize UTC before binding so asyncpg does not reject an aware value.
-    timeout_at = datetime.now(timezone.utc).replace(tzinfo=None) + timedelta(
+    timeout_at = datetime.now(UTC).replace(tzinfo=None) + timedelta(
         seconds=timeout_seconds
     )
 
diff --git a/apps/api/src/services/runtime_correlation.py b/apps/api/src/services/runtime_correlation.py
index d0775dfb0..68c162271 100644
--- a/apps/api/src/services/runtime_correlation.py
+++ b/apps/api/src/services/runtime_correlation.py
@@ -75,10 +75,10 @@ def canonical_traceparent(run_id: UUID) -> str:
     """Derive a stable W3C traceparent from one durable run identifier."""
 
     trace_hex = hashlib.sha256(
-        f"awooop-runtime-trace:{run_id}".encode("utf-8")
+        f"awooop-runtime-trace:{run_id}".encode()
     ).hexdigest()[:32]
     span_hex = hashlib.sha256(
-        f"awooop-runtime-root-span:{run_id}".encode("utf-8")
+        f"awooop-runtime-root-span:{run_id}".encode()
     ).hexdigest()[:16]
     return f"00-{trace_hex}-{span_hex}-01"