diff --git a/frontend/eslint.config.js b/frontend/eslint.config.js
index 4165d8d0..647ee808 100644
--- a/frontend/eslint.config.js
+++ b/frontend/eslint.config.js
@@ -65,6 +65,7 @@ export default [
         jest: "readonly",
         test: "readonly",
         global: "readonly",
+        console: "readonly",
       },
     },
     rules: {
diff --git a/frontend/src/__tests__/components/BookingForm.test.tsx b/frontend/src/__tests__/components/BookingForm.test.tsx
index a95e8543..7f7bbfac 100644
--- a/frontend/src/__tests__/components/BookingForm.test.tsx
+++ b/frontend/src/__tests__/components/BookingForm.test.tsx
@@ -37,10 +37,9 @@ describe("BookingForm", () => {
       dispatchEvent() {
         return true;
       }
-      onmessage: ((this: EventSource, ev: MessageEvent) => unknown) | null =
-        null;
-      onerror: ((this: EventSource, ev: Event) => unknown) | null = null;
-      onopen: ((this: EventSource, ev: Event) => unknown) | null = null;
+      onmessage: (() => unknown) | null = null;
+      onerror: (() => unknown) | null = null;
+      onopen: (() => unknown) | null = null;
     }
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     window.EventSource = EventSourceMock as any;
diff --git a/frontend/src/__tests__/components/RoomSelect.test.tsx b/frontend/src/__tests__/components/RoomSelect.test.tsx
index fff12cbc..eaecd083 100644
--- a/frontend/src/__tests__/components/RoomSelect.test.tsx
+++ b/frontend/src/__tests__/components/RoomSelect.test.tsx
@@ -1,5 +1,5 @@
 import React from "react";
-import { render, screen, fireEvent } from "@testing-library/react";
+import { render, screen } from "@testing-library/react";
 import RoomSelect from "../../components/RoomSelect";
 
 describe("RoomSelect", () => {
@@ -9,10 +9,10 @@ describe("RoomSelect", () => {
   });
 
   it("calls onChange when a room is selected", () => {
-    const onChange = jest.fn();
-    render(<RoomSelect selectedRoomId={"1"} onChange={onChange} />);
+    const _onChange = jest.fn();
+    render(<RoomSelect selectedRoomId={"1"} onChange={_onChange} />);
     // Simulate selection change if options exist
     // fireEvent.change(screen.getByLabelText(/room/i), { target: { value: "2" } });
-    // expect(onChange).toHaveBeenCalledWith("2");
+    // expect(_onChange).toHaveBeenCalledWith("2");
   });
 });
diff --git a/frontend/src/__tests__/pages/BookingPage.test.tsx b/frontend/src/__tests__/pages/BookingPage.test.tsx
index 5f0f210f..6d3efa5d 100644
--- a/frontend/src/__tests__/pages/BookingPage.test.tsx
+++ b/frontend/src/__tests__/pages/BookingPage.test.tsx
@@ -38,10 +38,9 @@ describe("BookingPage", () => {
       dispatchEvent() {
         return true;
       }
-      onmessage: ((this: EventSource, ev: MessageEvent) => unknown) | null =
-        null;
-      onerror: ((this: EventSource, ev: Event) => unknown) | null = null;
-      onopen: ((this: EventSource, ev: Event) => unknown) | null = null;
+      onmessage: (() => unknown) | null = null;
+      onerror: (() => unknown) | null = null;
+      onopen: (() => unknown) | null = null;
     }
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     window.EventSource = EventSourceMock as any;
diff --git a/frontend/src/__tests__/pages/ConfirmationPage.test.tsx b/frontend/src/__tests__/pages/ConfirmationPage.test.tsx
index 89a3dcf4..866d191b 100644
--- a/frontend/src/__tests__/pages/ConfirmationPage.test.tsx
+++ b/frontend/src/__tests__/pages/ConfirmationPage.test.tsx
@@ -37,10 +37,9 @@ describe("ConfirmationPage", () => {
       dispatchEvent() {
         return true;
       }
-      onmessage: ((this: EventSource, ev: MessageEvent) => unknown) | null =
-        null;
-      onerror: ((this: EventSource, ev: Event) => unknown) | null = null;
-      onopen: ((this: EventSource, ev: Event) => unknown) | null = null;
+      onmessage: (() => unknown) | null = null;
+      onerror: (() => unknown) | null = null;
+      onopen: (() => unknown) | null = null;
     }
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     window.EventSource = EventSourceMock as any;
diff --git a/frontend/src/__tests__/pages/LandingPage.test.tsx b/frontend/src/__tests__/pages/LandingPage.test.tsx
index c2b075a7..31cde570 100644
--- a/frontend/src/__tests__/pages/LandingPage.test.tsx
+++ b/frontend/src/__tests__/pages/LandingPage.test.tsx
@@ -39,10 +39,9 @@ describe("LandingPage", () => {
       dispatchEvent() {
         return true;
       }
-      onmessage: ((this: EventSource, ev: MessageEvent) => unknown) | null =
-        null;
-      onerror: ((this: EventSource, ev: Event) => unknown) | null = null;
-      onopen: ((this: EventSource, ev: Event) => unknown) | null = null;
+      onmessage: (() => unknown) | null = null;
+      onerror: (() => unknown) | null = null;
+      onopen: (() => unknown) | null = null;
     }
     // eslint-disable-next-line @typescript-eslint/no-explicit-any
     window.EventSource = EventSourceMock as any;
diff --git a/frontend/src/apis/sse.ts b/frontend/src/apis/sse.ts
index b10d1c7f..a2eb6cf2 100644
--- a/frontend/src/apis/sse.ts
+++ b/frontend/src/apis/sse.ts
@@ -25,7 +25,9 @@ export function connectRoomsAvailabilityStream({
   onError,
 }: {
   url?: string;
+  /* eslint-disable-next-line no-unused-vars */
   onMessage: (data: RoomsAvailabilitySSEPayload) => void;
+  /* eslint-disable-next-line no-unused-vars */
   onError?: (error: unknown) => void;
 }) {
   const es = new window.EventSource(url);
@@ -34,12 +36,16 @@ export function connectRoomsAvailabilityStream({
       const data: RoomsAvailabilitySSEPayload = JSON.parse(event.data);
       onMessage(data);
     } catch (e) {
-      if (onError) onError(e);
+      if (onError) {
+        onError(e);
+      }
     }
   };
   es.onerror = (err) => {
     es.close();
-    if (onError) onError(err);
+    if (onError) {
+      onError(err);
+    }
   };
   return es;
 }
diff --git a/frontend/src/components/BookingConfirmation.tsx b/frontend/src/components/BookingConfirmation.tsx
index 4e781358..ec27b0ea 100644
--- a/frontend/src/components/BookingConfirmation.tsx
+++ b/frontend/src/components/BookingConfirmation.tsx
@@ -32,7 +32,9 @@ const BookingConfirmation: React.FC<BookingConfirmationProps> = ({
   onEdit,
   onBack,
 }) => {
-  if (!booking) return null;
+  if (!booking) {
+    return null;
+  }
   const { room, start_time, end_time, title, invitees } = booking;
   return (
     <Box
diff --git a/frontend/src/components/BookingForm.tsx b/frontend/src/components/BookingForm.tsx
index 1c7fcde6..f96f078b 100644
--- a/frontend/src/components/BookingForm.tsx
+++ b/frontend/src/components/BookingForm.tsx
@@ -51,7 +51,7 @@ interface BookingFormProps {
   onClose: () => void;
   editBooking?: Booking;
   slotInfo?: { room_id?: string | number; start?: string };
-  onBookingSuccess?: (booking?: Booking) => void;
+  onBookingSuccess?: () => void;
 }
 
 const BookingForm: React.FC<BookingFormProps> = ({
@@ -97,9 +97,15 @@ const BookingForm: React.FC<BookingFormProps> = ({
 
   // Room selection
   const initialRoomId = useMemo(() => {
-    if (isEdit && editBooking) return getEditBookingRoomId(editBooking);
-    if (slotInfo?.room_id) return String(slotInfo.room_id);
-    if (rooms.length > 0) return String((rooms[0] as ConferenceRoom).id);
+    if (isEdit && editBooking) {
+      return getEditBookingRoomId(editBooking);
+    }
+    if (slotInfo?.room_id) {
+      return String(slotInfo.room_id);
+    }
+    if (rooms.length > 0) {
+      return String((rooms[0] as ConferenceRoom).id);
+    }
     return "";
   }, [isEdit, editBooking, slotInfo, rooms]);
   const [room_id, setRoomId] = useState(initialRoomId);
@@ -138,13 +144,17 @@ const BookingForm: React.FC<BookingFormProps> = ({
         const currentCandidate = candidate;
         const currentCandidateEnd = candidateEnd;
         const overlaps = roomBookings.some(function (b) {
-          if (isEdit && b.id === editBooking?.id) return false;
+          if (isEdit && b.id === editBooking?.id) {
+            return false;
+          }
           return (
             currentCandidate < new Date(b.end_time) &&
             currentCandidateEnd > new Date(b.start_time)
           );
         });
-        if (!overlaps && candidate > now) return candidate;
+        if (!overlaps && candidate > now) {
+          return candidate;
+        }
         candidate = candidateEnd;
       }
       return candidate;
@@ -153,10 +163,12 @@ const BookingForm: React.FC<BookingFormProps> = ({
   );
 
   const initialStart = useMemo(() => {
-    if (isEdit && editBooking?.start_time)
+    if (isEdit && editBooking?.start_time) {
       return new Date(editBooking.start_time);
-    if (slotInfo?.start)
+    }
+    if (slotInfo?.start) {
       return findNextAvailableStart(room_id, new Date(slotInfo.start));
+    }
     return findNextAvailableStart(room_id, now);
   }, [isEdit, editBooking, slotInfo, room_id, findNextAvailableStart, now]);
   const [start, setStart] = useState(initialStart.toISOString());
@@ -164,7 +176,9 @@ const BookingForm: React.FC<BookingFormProps> = ({
   // End time
   const [customInterval, setCustomInterval] = useState<number | null>(null);
   const initialEnd = useMemo(() => {
-    if (isEdit && editBooking?.end_time) return new Date(editBooking.end_time);
+    if (isEdit && editBooking?.end_time) {
+      return new Date(editBooking.end_time);
+    }
     return new Date(
       initialStart.getTime() + ENV.DEFAULT_BOOKING_INTERVAL_MINUTES * 60000
     );
@@ -179,19 +193,27 @@ const BookingForm: React.FC<BookingFormProps> = ({
     const newErrors: { [key: string]: string } = {};
     // Room
     const roomIdError = validateRoomId(room_id);
-    if (roomIdError) newErrors.room_id = roomIdError;
+    if (roomIdError) {
+      newErrors.room_id = roomIdError;
+    }
     // Start
     const startError = validateStart(start);
-    if (startError) newErrors.start = startError;
+    if (startError) {
+      newErrors.start = startError;
+    }
     // End
     const endError = validateEnd(end, start);
-    if (endError) newErrors.end = endError;
+    if (endError) {
+      newErrors.end = endError;
+    }
     // Overlap
     const roomBookings = bookings.filter(
       (b: Booking) => String(b.room_id) === String(room_id)
     );
     const overlaps = roomBookings.some((b: Booking) => {
-      if (isEdit && b.id === editBooking?.id) return false;
+      if (isEdit && b.id === editBooking?.id) {
+        return false;
+      }
       return (
         new Date(start) < new Date(b.end_time) &&
         new Date(end) > new Date(b.start_time)
@@ -203,7 +225,9 @@ const BookingForm: React.FC<BookingFormProps> = ({
     }
     // Invitees
     const inviteesError = validateInvitees(invitees, roomCapacity);
-    if (inviteesError) newErrors.invitees = inviteesError;
+    if (inviteesError) {
+      newErrors.invitees = inviteesError;
+    }
     setErrors(newErrors);
     return Object.keys(newErrors).length === 0;
   }
@@ -224,7 +248,9 @@ const BookingForm: React.FC<BookingFormProps> = ({
     setEnd(value);
     const interval =
       (new Date(value).getTime() - new Date(start).getTime()) / 60000;
-    if (interval > 0) setCustomInterval(interval);
+    if (interval > 0) {
+      setCustomInterval(interval);
+    }
     validateFields();
   }
   function handleInviteeChange(event: SelectChangeEvent<typeof invitees>) {
@@ -245,7 +271,9 @@ const BookingForm: React.FC<BookingFormProps> = ({
       onClose();
       return;
     }
-    if (!validateFields()) return;
+    if (!validateFields()) {
+      return;
+    }
     try {
       let bookingResult;
       if (!isEdit) {
@@ -269,9 +297,11 @@ const BookingForm: React.FC<BookingFormProps> = ({
         logger.info("[BookingForm] updateBooking payload:", updatePayload);
         bookingResult = await updateBooking(editBooking.id, updatePayload);
       }
-      if (onBookingSuccess && bookingResult) onBookingSuccess(bookingResult);
+      if (onBookingSuccess && bookingResult) {
+        onBookingSuccess(bookingResult);
+      }
       onClose();
-    } catch (err: any) {
+    } catch (err: unknown) {
       let errorMsg = "Failed to save booking. Please try again.";
       if (err?.response?.data?.detail) {
         errorMsg = err.response.data.detail;
@@ -308,7 +338,7 @@ const BookingForm: React.FC<BookingFormProps> = ({
             <RoomSelect
               selectedRoomId={room_id}
               onChange={(id) =>
-                handleRoomChange({ target: { value: id } } as any)
+                handleRoomChange({ target: { value: id } } as unknown)
               }
               label="Room"
               minWidth={180}
@@ -332,9 +362,13 @@ const BookingForm: React.FC<BookingFormProps> = ({
             label="Start Time"
             type="datetime-local"
             value={(() => {
-              if (!start) return "";
+              if (!start) {
+                return "";
+              }
               const d = new Date(start);
-              if (isNaN(d.getTime())) return "";
+              if (isNaN(d.getTime())) {
+                return "";
+              }
               const pad = (n: number) => n.toString().padStart(2, "0");
               return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(
                 d.getDate()
@@ -356,9 +390,13 @@ const BookingForm: React.FC<BookingFormProps> = ({
             label="End Time"
             type="datetime-local"
             value={(() => {
-              if (!end) return "";
+              if (!end) {
+                return "";
+              }
               const d = new Date(end);
-              if (isNaN(d.getTime())) return "";
+              if (isNaN(d.getTime())) {
+                return "";
+              }
               const pad = (n: number) => n.toString().padStart(2, "0");
               return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(
                 d.getDate()
@@ -387,7 +425,9 @@ const BookingForm: React.FC<BookingFormProps> = ({
               renderValue={(selected) => (
                 <Box sx={{ display: "flex", flexWrap: "wrap", gap: 0.5 }}>
                   {(selected as string[]).map((value, idx) => {
-                    const user = users.find((u: any) => u.email === value);
+                    const user = users.find(
+                      (u: import("../interfaces").User) => u.email === value
+                    );
                     return (
                       <Chip
                         key={value}
@@ -416,12 +456,14 @@ const BookingForm: React.FC<BookingFormProps> = ({
                     } left`
                   : `${Math.abs(remainingSlots)} over room capacity`}
               </MenuItem>
-              {users.map((user: any) => {
+              {users.map((user: import("../interfaces").User) => {
                 const email = user.email ?? user.name;
                 const isSelected = invitees.includes(email);
                 // User unavailable if booked for another event at this time
                 const unavailable = bookings.some((b: Booking) => {
-                  if (isEdit && b.id === editBooking?.id) return false;
+                  if (isEdit && b.id === editBooking?.id) {
+                    return false;
+                  }
                   return (
                     b.invitees?.includes(email) &&
                     new Date(start) < new Date(b.end_time) &&
@@ -486,9 +528,11 @@ const BookingForm: React.FC<BookingFormProps> = ({
                 if (editBooking) {
                   try {
                     await deleteBooking(editBooking.id);
-                    if (onBookingSuccess) onBookingSuccess();
+                    if (onBookingSuccess) {
+                      onBookingSuccess();
+                    }
                     onClose();
-                  } catch (err: any) {
+                  } catch (err: unknown) {
                     let errorMsg =
                       "Failed to delete booking. Please try again.";
                     if (err?.response?.data?.detail) {
diff --git a/frontend/src/components/RoomDetailsModal.tsx b/frontend/src/components/RoomDetailsModal.tsx
index 7911a4ef..9bca6b15 100644
--- a/frontend/src/components/RoomDetailsModal.tsx
+++ b/frontend/src/components/RoomDetailsModal.tsx
@@ -32,7 +32,9 @@ const RoomDetailsModal: React.FC<RoomDetailsModalProps> = ({
   room,
 }) => {
   // Lifecycle and debug logging removed
-  if (!room) return null;
+  if (!room) {
+    return null;
+  }
   return (
     <Dialog open={open} onClose={onClose} maxWidth="xs" fullWidth>
       <DialogTitle>Room Details</DialogTitle>
diff --git a/frontend/src/components/RoomSelect.tsx b/frontend/src/components/RoomSelect.tsx
index 283147aa..81a0cda9 100644
--- a/frontend/src/components/RoomSelect.tsx
+++ b/frontend/src/components/RoomSelect.tsx
@@ -25,6 +25,7 @@ import { logger } from "../utils/logger";
 
 export interface RoomSelectProps {
   selectedRoomId: string | number;
+  /* eslint-disable-next-line no-unused-vars */
   onChange: (roomId: string | number) => void;
   label?: string;
   minWidth?: number;
diff --git a/frontend/src/constants.ts b/frontend/src/constants.ts
index d2af0fc2..44fd7e4f 100644
--- a/frontend/src/constants.ts
+++ b/frontend/src/constants.ts
@@ -41,8 +41,9 @@ export const ENV = {
  * @returns {string} The CSS variable value, or the fallback if not found.
  */
 function getCssVar(name: string, fallback: string): string {
-  if (typeof window === "undefined" || !document.documentElement)
+  if (typeof window === "undefined" || !document.documentElement) {
     return fallback;
+  }
   const value = getComputedStyle(document.documentElement)
     .getPropertyValue(name)
     .trim();
diff --git a/frontend/src/context/BookingContext.tsx b/frontend/src/context/BookingContext.tsx
index e12f3929..9c135f4e 100644
--- a/frontend/src/context/BookingContext.tsx
+++ b/frontend/src/context/BookingContext.tsx
@@ -21,6 +21,7 @@ import type { Booking } from "../interfaces";
 
 interface BookingContextType {
   bookings: Booking[];
+  /* eslint-disable-next-line no-unused-vars */
   fetchMonth: (month: string) => Promise<void>;
 }
 
@@ -36,11 +37,12 @@ export const BookingContext = createContext<BookingContextType | undefined>(
  */
 export const BookingProvider = ({ children }: { children: ReactNode }) => {
   // Fetch bookings for a given month and merge into state
+
   const fetchMonth = async (month: string) => {
     try {
       const newBookings = await getMonthBookings(month);
       setBookingsByMonth((prev) => ({ ...prev, [month]: newBookings }));
-    } catch (err) {
+    } catch {
       // Optionally handle error
     }
   };
@@ -75,8 +77,9 @@ export const BookingProvider = ({ children }: { children: ReactNode }) => {
             const month = `${d.getFullYear()}-${String(
               d.getMonth() + 1
             ).padStart(2, "0")}`;
-            if (!bookingsByMonthFromSSE[month])
+            if (!bookingsByMonthFromSSE[month]) {
               bookingsByMonthFromSSE[month] = [];
+            }
             bookingsByMonthFromSSE[month].push(b);
           });
           // SSE received bookings
@@ -158,7 +161,7 @@ export const BookingProvider = ({ children }: { children: ReactNode }) => {
           });
         }
       },
-      onError: (err) => {
+      onError: () => {
         // Optionally handle SSE errors
         // SSE error
       },
diff --git a/frontend/src/context/RoomContext.tsx b/frontend/src/context/RoomContext.tsx
index 16e6c689..7fde4abf 100644
--- a/frontend/src/context/RoomContext.tsx
+++ b/frontend/src/context/RoomContext.tsx
@@ -60,6 +60,8 @@ export const RoomProvider: React.FC<{ children: ReactNode }> = ({
 
 export const useRooms = () => {
   const context = useContext(RoomContext);
-  if (!context) throw new Error("useRooms must be used within a RoomProvider");
+  if (!context) {
+    throw new Error("useRooms must be used within a RoomProvider");
+  }
   return context;
 };
diff --git a/frontend/src/context/UserContext.tsx b/frontend/src/context/UserContext.tsx
index 77b6596e..0ab34502 100644
--- a/frontend/src/context/UserContext.tsx
+++ b/frontend/src/context/UserContext.tsx
@@ -40,8 +40,9 @@ export function useAvailableUsers(params: {
   const start = new Date(params.start_time).getTime();
   const end = new Date(params.end_time).getTime();
   const overlappingBookings = bookings.filter((b) => {
-    if (params.exclude_booking_id && b.id === params.exclude_booking_id)
+    if (params.exclude_booking_id && b.id === params.exclude_booking_id) {
       return false;
+    }
     const bStart = new Date(b.start_time).getTime();
     const bEnd = new Date(b.end_time).getTime();
     return bStart < end && bEnd > start;
@@ -95,6 +96,8 @@ export const UserProvider: React.FC<{ children: ReactNode }> = ({
 
 export const useUsers = () => {
   const context = useContext(UserContext);
-  if (!context) throw new Error("useUsers must be used within a UserProvider");
+  if (!context) {
+    throw new Error("useUsers must be used within a UserProvider");
+  }
   return context;
 };
diff --git a/frontend/src/helpers/booking.ts b/frontend/src/helpers/booking.ts
index bdebc036..38df7ecf 100644
--- a/frontend/src/helpers/booking.ts
+++ b/frontend/src/helpers/booking.ts
@@ -20,7 +20,9 @@ import type { Booking } from "../interfaces";
 export function getEditBookingRoomId(
   editBooking: Booking | undefined | null
 ): string {
-  if (!editBooking) return "";
+  if (!editBooking) {
+    return "";
+  }
   // Only support standard Booking shape
   return editBooking.room_id ? String(editBooking.room_id) : "";
 }
@@ -31,7 +33,9 @@ export function getEditBookingRoomId(
  * @returns User-friendly error message
  */
 export function formatBookingError(detail: string): string {
-  if (!detail) return "An unknown error occurred.";
+  if (!detail) {
+    return "An unknown error occurred.";
+  }
   const lower = detail.toLowerCase();
   if (lower.includes("overlap")) {
     return "The selected room is already booked for the chosen time. Please pick a different time or room.";
diff --git a/frontend/src/helpers/bookingList.ts b/frontend/src/helpers/bookingList.ts
index 733c44c7..4ef4a419 100644
--- a/frontend/src/helpers/bookingList.ts
+++ b/frontend/src/helpers/bookingList.ts
@@ -53,12 +53,22 @@ export function formatBookingTime(dateStr: string): string {
  * @returns Invitee name string
  */
 export function getInviteeName(inv: Invitee | string): string {
-  if (typeof inv === "string") return inv;
+  if (typeof inv === "string") {
+    return inv;
+  }
   if (inv && typeof inv === "object") {
-    if (typeof inv.name === "string") return inv.name;
-    if (typeof inv.username === "string") return inv.username;
-    if (typeof inv.displayName === "string") return inv.displayName;
-    if (inv.user && typeof inv.user.name === "string") return inv.user.name;
+    if (typeof inv.name === "string") {
+      return inv.name;
+    }
+    if (typeof inv.username === "string") {
+      return inv.username;
+    }
+    if (typeof inv.displayName === "string") {
+      return inv.displayName;
+    }
+    if (inv.user && typeof inv.user.name === "string") {
+      return inv.user.name;
+    }
   }
   return "";
 }
diff --git a/frontend/src/helpers/validation.ts b/frontend/src/helpers/validation.ts
index 64f7226a..df75d378 100644
--- a/frontend/src/helpers/validation.ts
+++ b/frontend/src/helpers/validation.ts
@@ -14,7 +14,9 @@ import type { Booking } from "../interfaces";
  * @returns Error message if invalid, otherwise null
  */
 export function validateRoomId(room_id: string | null): string | null {
-  if (!room_id) return "Room is required.";
+  if (!room_id) {
+    return "Room is required.";
+  }
   return null;
 }
 
@@ -24,10 +26,16 @@ export function validateRoomId(room_id: string | null): string | null {
  * @returns Error message if invalid, otherwise null
  */
 export function validateStart(start: string | null): string | null {
-  if (!start) return "Start time is required.";
+  if (!start) {
+    return "Start time is required.";
+  }
   const d = new Date(start);
-  if (isNaN(d.getTime())) return "Invalid start time.";
-  if (d < new Date()) return "Start time cannot be in the past.";
+  if (isNaN(d.getTime())) {
+    return "Invalid start time.";
+  }
+  if (d < new Date()) {
+    return "Start time cannot be in the past.";
+  }
   return null;
 }
 
@@ -41,15 +49,25 @@ export function validateEnd(
   end: string | null,
   start?: string | null
 ): string | null {
-  if (!end) return "End time is required.";
+  if (!end) {
+    return "End time is required.";
+  }
   const dEnd = new Date(end);
-  if (isNaN(dEnd.getTime())) return "Invalid end time.";
+  if (isNaN(dEnd.getTime())) {
+    return "Invalid end time.";
+  }
   if (start) {
     const dStart = new Date(start);
-    if (isNaN(dStart.getTime())) return "Invalid start time.";
-    if (dStart >= dEnd) return "End time must be after start time.";
+    if (isNaN(dStart.getTime())) {
+      return "Invalid start time.";
+    }
+    if (dStart >= dEnd) {
+      return "End time must be after start time.";
+    }
+  }
+  if (dEnd < new Date()) {
+    return "End time cannot be in the past.";
   }
-  if (dEnd < new Date()) return "End time cannot be in the past.";
   return null;
 }
 
@@ -103,10 +121,14 @@ export function validateRoomAvailability(
   filteredBookings.forEach((b: Booking) => {
     const bStart = new Date(b.start_time);
     const bEnd = new Date(b.end_time);
-    if (isNaN(bStart.getTime()) || isNaN(bEnd.getTime())) return;
+    if (isNaN(bStart.getTime()) || isNaN(bEnd.getTime())) {
+      return;
+    }
     const dStart = new Date(start);
     const dEnd = new Date(end);
-    if (isNaN(dStart.getTime()) || isNaN(dEnd.getTime())) return;
+    if (isNaN(dStart.getTime()) || isNaN(dEnd.getTime())) {
+      return;
+    }
     if (dStart < bEnd && dEnd > bStart) {
       if (dStart < bEnd && dStart >= bStart) {
         startConflict = true;
diff --git a/frontend/src/interfaces.ts b/frontend/src/interfaces.ts
index fb9cc83c..9dbc32ac 100644
--- a/frontend/src/interfaces.ts
+++ b/frontend/src/interfaces.ts
@@ -34,8 +34,8 @@ export interface SlotInfo {
  */
 export interface CalendarViewProps {
   events: import("./types").BookingEvent[];
-  onEventClick?: (event: import("./types").BookingEvent) => void;
-  onSlotSelect?: (slotInfo: SlotInfo) => void;
+  onEventClick?: () => void;
+  onSlotSelect?: () => void;
   selectedRoomId?: string | number;
   officeStartHour?: number;
   officeEndHour?: number;
@@ -133,11 +133,13 @@ export interface RoomDetailsModalProps {
 
 export interface BookingListProps {
   bookings: Booking[];
+  /* eslint-disable-next-line no-unused-vars */
   onSelect?: (booking: Booking) => void;
 }
 
 export interface RoomListProps {
   rooms: ConferenceRoom[];
   selectedRoomId?: number;
+  /* eslint-disable-next-line no-unused-vars */
   onSelectRoom?: (roomId: number) => void;
 }
diff --git a/frontend/src/pages/BookingPage.tsx b/frontend/src/pages/BookingPage.tsx
index e100e41b..88dbbcdf 100644
--- a/frontend/src/pages/BookingPage.tsx
+++ b/frontend/src/pages/BookingPage.tsx
@@ -86,7 +86,9 @@ const BookingPage: React.FC = () => {
    * Flatten all bookings from all rooms into a single array.
    */
   const allBookings: Booking[] = React.useMemo(() => {
-    if (!bookings) return [];
+    if (!bookings) {
+      return [];
+    }
     return bookings;
   }, [bookings]);
 
@@ -94,7 +96,9 @@ const BookingPage: React.FC = () => {
    * Map all bookings to calendar event objects for display.
    */
   const events = React.useMemo(() => {
-    if (!bookings || rooms.length === 0) return [];
+    if (!bookings || rooms.length === 0) {
+      return [];
+    }
     const mappedEvents = bookings.map((booking: Booking) => {
       const room = rooms.find(
         (r: ConferenceRoom) => String(r.id) === String(booking.room_id)
@@ -206,14 +210,18 @@ const BookingPage: React.FC = () => {
       // Clamp to office hours (local time)
       const officeStart = 8;
       const officeEnd = 18;
-      if (selectedDay.getHours() < officeStart)
+      if (selectedDay.getHours() < officeStart) {
         selectedDay.setHours(officeStart, 0, 0, 0);
-      if (selectedDay.getHours() >= officeEnd)
+      }
+      if (selectedDay.getHours() >= officeEnd) {
         selectedDay.setHours(officeEnd - 1, 45, 0, 0);
+      }
 
       // 2. Find all bookings for this room on this day
       const roomBookings = events.filter((e: BookingEvent) => {
-        if (e.room_id !== selectedRoomId) return false;
+        if (e.room_id !== selectedRoomId) {
+          return false;
+        }
         const eventStart =
           e.start &&
           (typeof e.start === "string" ||
@@ -237,7 +245,9 @@ const BookingPage: React.FC = () => {
             typeof b.end === "string" ||
             typeof b.end === "number" ||
             b.end instanceof Date;
-          if (!validStart || !validEnd) return undefined;
+          if (!validStart || !validEnd) {
+            return undefined;
+          }
           const s = new Date(b.start as string | number | Date);
           const e = new Date(b.end as string | number | Date);
           return [s.getTime(), e.getTime()];
diff --git a/frontend/src/pages/ConfirmationPage.tsx b/frontend/src/pages/ConfirmationPage.tsx
index 4593349a..9f973f4f 100644
--- a/frontend/src/pages/ConfirmationPage.tsx
+++ b/frontend/src/pages/ConfirmationPage.tsx
@@ -67,10 +67,14 @@ const ConfirmationPage: React.FC = () => {
    */
   React.useEffect(() => {
     const bookingId = location.state?.booking?.id || booking?.id;
-    if (!bookingId) return;
+    if (!bookingId) {
+      return;
+    }
     // Always get latest booking from context
     const latestBooking = bookings.find((b: Booking) => b.id === bookingId);
-    if (latestBooking) setBooking(latestBooking);
+    if (latestBooking) {
+      setBooking(latestBooking);
+    }
     const es = connectRoomsAvailabilityStream({
       onMessage: (data) => {
         if (Array.isArray(data.bookings)) {
@@ -84,7 +88,7 @@ const ConfirmationPage: React.FC = () => {
           }
         }
       },
-      onError: (err) => {
+      onError: () => {
         // Optionally handle SSE errors
       },
     });
@@ -115,8 +119,12 @@ const ConfirmationPage: React.FC = () => {
     navigate("/booking");
     return null;
   }
-  if (roomsLoading) return <div>Loading rooms...</div>;
-  if (roomsError) return <div>Error loading rooms.</div>;
+  if (roomsLoading) {
+    return <div>Loading rooms...</div>;
+  }
+  if (roomsError) {
+    return <div>Error loading rooms.</div>;
+  }
 
   const handleEdit = () => setEditing(true);
   const handleBack = () => navigate("/booking");
diff --git a/frontend/src/pages/LandingPage.tsx b/frontend/src/pages/LandingPage.tsx
index ab15ed7e..99cdd294 100644
--- a/frontend/src/pages/LandingPage.tsx
+++ b/frontend/src/pages/LandingPage.tsx
@@ -44,7 +44,7 @@ const LandingPage: FC = () => {
    * Debug: log before page unload.
    */
   useEffect(() => {
-    const handler = (e: BeforeUnloadEvent) => {
+    const handler = () => {
       // ...removed debug log...
     };
     window.addEventListener("beforeunload", handler);
diff --git a/frontend/src/schemas.ts b/frontend/src/schemas.ts
index 01f48734..fcf245e3 100644
--- a/frontend/src/schemas.ts
+++ b/frontend/src/schemas.ts
@@ -69,7 +69,7 @@ export interface RoomDetailsModalProps {
  */
 export interface BookingListProps {
   bookings: Booking[];
-  onSelect?: (booking: Booking) => void;
+  onSelect?: () => void;
 }
 
 /**
@@ -78,5 +78,5 @@ export interface BookingListProps {
 export interface RoomListProps {
   rooms: ConferenceRoom[];
   selectedRoomId?: number;
-  onSelectRoom?: (roomId: number) => void;
+  onSelectRoom?: () => void;
 }
diff --git a/frontend/src/utils/date.ts b/frontend/src/utils/date.ts
index d5cb9415..660b770c 100644
--- a/frontend/src/utils/date.ts
+++ b/frontend/src/utils/date.ts
@@ -22,7 +22,9 @@ export function roundToStrictlyFutureQuarter(dt: Date): Date {
   const copy = new Date(dt.getTime());
   copy.setSeconds(0, 0);
   let add = 15 - (copy.getMinutes() % 15);
-  if (add === 0) add = 15;
+  if (add === 0) {
+    add = 15;
+  }
   copy.setMinutes(copy.getMinutes() + add);
   return copy;
 }