diff --git a/.gitignore b/.gitignore
index 8c0dfcd4..f9ea124f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,3 +10,6 @@ docs/doxygen/
 
 # DAQ output data
 scripts/postprocessing/output/
+
+# Internal review notes (not shared with the team)
+daq-server/BACKEND_REVIEW.md
diff --git a/daq-server/diablo_server/backend/src/server.ts b/daq-server/diablo_server/backend/src/server.ts
index b6f8227d..89611119 100644
--- a/daq-server/diablo_server/backend/src/server.ts
+++ b/daq-server/diablo_server/backend/src/server.ts
@@ -801,7 +801,12 @@ function handleCommand(ws: WebSocket, command: CommandPayload): void {
       break;
     }
     case 'extend_fire':
-      sendToActuatorService('EXTEND_FIRE\n').catch(() => { });
+      sendToActuatorService('EXTEND_FIRE\n').then(({ ok, reply }) => {
+        console.log(`[ThinServer] Extend fire: ${ok ? 'OK' : 'FAIL'} (${reply})`);
+        if (!ok) {
+          send(ws, { type: MessageType.ERROR, timestamp: Date.now(), payload: { message: `Extend fire failed: ${reply}` } });
+        }
+      });
       break;
     case 'set_countdown_target':
       countdownTargetMs = command.data.targetTimeMs ?? null;
@@ -1002,9 +1007,19 @@ elodin.on('packet', (header: any, payload: Buffer) => {
       broadcastCommandedActuatorsForState(currentState);
       scheduleActuatorMismatchCheck(currentState);
       if (currentState === SystemState.FIRE && prevState !== SystemState.FIRE) {
-        sendToControllerService('FIRE_START\n').catch(() => { /* non-fatal */ });
+        sendToControllerService('FIRE_START\n').then(({ ok, reply }) => {
+          if (!ok) {
+            console.error(`[ThinServer] FIRE_START not acknowledged by controller_service: ${reply}`);
+            broadcastNotification({ key: 'fire_start_failed', category: 'error', message: `FIRE_START not acknowledged by controller: ${reply}`, timestampMs: Date.now(), ongoing: false });
+          }
+        });
       } else if (prevState === SystemState.FIRE && currentState !== SystemState.FIRE) {
-        sendToControllerService('FIRE_STOP\n').catch(() => { /* non-fatal */ });
+        sendToControllerService('FIRE_STOP\n').then(({ ok, reply }) => {
+          if (!ok) {
+            console.error(`[ThinServer] FIRE_STOP not acknowledged by controller_service: ${reply}`);
+            broadcastNotification({ key: 'fire_stop_failed', category: 'error', message: `FIRE_STOP not acknowledged by controller: ${reply}`, timestampMs: Date.now(), ongoing: false });
+          }
+        });
       }
       return;
     }
diff --git a/firmware/platformio-common.ini b/firmware/platformio-common.ini
index 70de3423..11a816ad 100644
--- a/firmware/platformio-common.ini
+++ b/firmware/platformio-common.ini
@@ -3,7 +3,6 @@
 ; Per-project platformio.ini files pull this in via:
 ;   [platformio]
 ;   extra_configs = ../../platformio-common.ini   ; adjust depth
-;
 ; ...then declare an [env:...] that `extends` one of the base
 ; sections below, e.g.:
 ;   [env:my_env]