diff --git a/apps/mobile/src/navigation/AppNavigator.tsx b/apps/mobile/src/navigation/AppNavigator.tsx
index 6058f7d..f0843b8 100644
--- a/apps/mobile/src/navigation/AppNavigator.tsx
+++ b/apps/mobile/src/navigation/AppNavigator.tsx
@@ -21,7 +21,7 @@ const byPrefixAndName = { fas: { bars: faBars } };
 
 type HeaderMenuProps = {
   navigation: {
-    navigate: (screen: 'CalendarImport' | 'Settings') => void;
+    navigate: (_screen: 'CalendarImport' | 'Settings') => void;
   };
 };
 
diff --git a/apps/mobile/src/screens/CalendarImportScreen.tsx b/apps/mobile/src/screens/CalendarImportScreen.tsx
index 6308116..5b51ec3 100644
--- a/apps/mobile/src/screens/CalendarImportScreen.tsx
+++ b/apps/mobile/src/screens/CalendarImportScreen.tsx
@@ -61,7 +61,7 @@ function CalendarCheckbox({
 }: {
   calendar: SelectableCalendar;
   selected: boolean;
-  onToggle: (id: string) => void;
+  onToggle: (_id: string) => void;
   colors: ReturnType<typeof useColors>;
 }) {
   const badgeColor = BADGE_COLORS[calendar.accountType] ?? BADGE_COLORS.other;
diff --git a/apps/mobile/src/screens/EventListScreen.tsx b/apps/mobile/src/screens/EventListScreen.tsx
index 2df02ca..a8a8d59 100644
--- a/apps/mobile/src/screens/EventListScreen.tsx
+++ b/apps/mobile/src/screens/EventListScreen.tsx
@@ -178,13 +178,6 @@ export function EventListScreen({ navigation }: ScreenProps) {
     const leaveCountdownLabel = leaveCountdown?.label;
     const leaveByLabel = leaveBy ? formatTime(leaveBy) : null;
     const trainLabel = selectedJourney?.trains.length ? selectedJourney.trains.join(', ') : 'Searching for train connection';
-    const status = leaveCountdown
-      ? leaveCountdown.label === 'Now'
-        ? 'Leave now'
-        : `Leave in ${leaveCountdown.label}`
-      : journeysLoading || destStation.loading
-        ? 'Calculating departure time'
-        : 'No connection';
 
     return (
       <View style={styles.cardWrapper}>
diff --git a/apps/web/src/app/add-event/AddEventModal.tsx b/apps/web/src/app/add-event/AddEventModal.tsx
index 1206697..a331135 100644
--- a/apps/web/src/app/add-event/AddEventModal.tsx
+++ b/apps/web/src/app/add-event/AddEventModal.tsx
@@ -33,8 +33,12 @@ const AddEventModal: React.FC<AddEventModalProps> = ({ isOpen, onClose, editEven
 
   const { addEvent, updateEvent } = useEventsStore();
 
-  // Populate fields when opening in edit mode
-  useEffect(() => {
+  // Track previous props to reset form fields when they change (avoids setState in useEffect)
+  const [prevEditEvent, setPrevEditEvent] = useState<Event | undefined>(editEvent);
+  const [prevIsOpen, setPrevIsOpen] = useState(isOpen);
+  if (editEvent !== prevEditEvent || isOpen !== prevIsOpen) {
+    setPrevEditEvent(editEvent);
+    setPrevIsOpen(isOpen);
     if (editEvent) {
       setTitle(editEvent.title);
       setDestination(editEvent.destination);
@@ -47,7 +51,7 @@ const AddEventModal: React.FC<AddEventModalProps> = ({ isOpen, onClose, editEven
       setEventTime("");
     }
     setSuccess(false);
-  }, [editEvent, isOpen]);
+  }
 
   const handleSubmit = async (e: React.FormEvent) => {
     e.preventDefault();
diff --git a/apps/web/src/app/calendar/GoogleTab.tsx b/apps/web/src/app/calendar/GoogleTab.tsx
index 23e6556..e654191 100644
--- a/apps/web/src/app/calendar/GoogleTab.tsx
+++ b/apps/web/src/app/calendar/GoogleTab.tsx
@@ -24,9 +24,28 @@ type GoogleTabProps = {
 };
 
 const GoogleTab: React.FC<GoogleTabProps> = ({ onEventsLoaded, className = "" }) => {
-  const [status, setStatus] = useState<GoogleStatus>("loading");
+  // Read and clean OAuth return params synchronously at mount (avoids setState in effect)
+  const [oauthParams] = useState<{ error: string | null; connected: string | null }>(() => {
+    if (typeof window === "undefined") return { error: null, connected: null };
+    const params = new URLSearchParams(window.location.search);
+    const error = params.get("google_error");
+    const connected = params.get("google_connected");
+    if (error || connected) {
+      const clean = new URL(window.location.href);
+      clean.searchParams.delete("google_connected");
+      clean.searchParams.delete("google_error");
+      window.history.replaceState(null, "", clean.toString());
+    }
+    return { error, connected };
+  });
+
+  const [status, setStatus] = useState<GoogleStatus>(
+    oauthParams.error ? "not-connected" : "loading"
+  );
   const [syncing, setSyncing] = useState(false);
-  const [error, setError] = useState<string | null>(null);
+  const [error, setError] = useState<string | null>(
+    oauthParams.error ? friendlyOAuthError(oauthParams.error) : null
+  );
   const [syncedCount, setSyncedCount] = useState<number | null>(null);
 
   const checkStatus = useCallback(async () => {
@@ -45,33 +64,6 @@ const GoogleTab: React.FC<GoogleTabProps> = ({ onEventsLoaded, className = "" })
     }
   }, []);
 
-  useEffect(() => {
-    // Handle OAuth return params
-    const params = new URLSearchParams(window.location.search);
-    const connected = params.get("google_connected");
-    const oauthError = params.get("google_error");
-
-    if (connected || oauthError) {
-      const clean = new URL(window.location.href);
-      clean.searchParams.delete("google_connected");
-      clean.searchParams.delete("google_error");
-      window.history.replaceState(null, "", clean.toString());
-    }
-
-    if (oauthError) {
-      setError(friendlyOAuthError(oauthError));
-      setStatus("not-connected");
-      return;
-    }
-
-    checkStatus().then(() => {
-      if (connected) {
-        syncEvents();
-      }
-    });
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, []);
-
   const syncEvents = useCallback(async () => {
     setSyncing(true);
     setError(null);
@@ -98,6 +90,19 @@ const GoogleTab: React.FC<GoogleTabProps> = ({ onEventsLoaded, className = "" })
     }
   }, [onEventsLoaded]);
 
+  useEffect(() => {
+    if (!oauthParams.error) {
+      // eslint-disable-next-line react-hooks/set-state-in-effect
+      checkStatus().then(() => {
+        if (oauthParams.connected) {
+          syncEvents();
+        }
+      });
+    }
+  // checkStatus and syncEvents are stable callbacks; oauthParams is a mount-time constant
+  // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, []);
+
   const disconnect = async () => {
     await fetch("/api/auth/google/disconnect", { method: "POST" });
     setStatus("not-connected");
diff --git a/apps/web/src/app/event/JourneyList.tsx b/apps/web/src/app/event/JourneyList.tsx
index 89db160..9b19363 100644
--- a/apps/web/src/app/event/JourneyList.tsx
+++ b/apps/web/src/app/event/JourneyList.tsx
@@ -34,7 +34,10 @@ const JourneyList: React.FC<JourneyListProps> = ({
   className = "",
 }) => {
   const [expanded, setExpanded] = useState(false);
-  const targetArrivalTime = new Date(eventTime.getTime() - arrivalBufferMinutes * 60000);
+  const targetArrivalTime = useMemo(
+    () => new Date(eventTime.getTime() - arrivalBufferMinutes * 60000),
+    [eventTime, arrivalBufferMinutes],
+  );
   const walkDurationMs = walkDurationSeconds * 1000;
   const rankedJourneys = useMemo(
     () => rankJourneys(journeys, targetArrivalTime, walkDurationMs),
diff --git a/apps/web/src/hooks/useEventsStore.tsx b/apps/web/src/hooks/useEventsStore.tsx
index 0d56cf0..2d6e377 100644
--- a/apps/web/src/hooks/useEventsStore.tsx
+++ b/apps/web/src/hooks/useEventsStore.tsx
@@ -45,13 +45,9 @@ const EventsContext = createContext<EventsContextType | undefined>(undefined);
  * Persists events to localStorage on every change (skips initial hydration write).
  */
 export function EventsProvider({ children }: { children: ReactNode }) {
-  const [events, setEventsState] = useState<Event[]>([]);
+  const [events, setEventsState] = useState<Event[]>(loadFromStorage);
   const skipInitialWrite = useRef(true);
 
-  useEffect(() => {
-    setEventsState(loadFromStorage());
-  }, []);
-
   useEffect(() => {
     if (skipInitialWrite.current) {
       skipInitialWrite.current = false;