diff --git a/src/actions.ts b/src/actions.ts
index e543434..063cf11 100644
--- a/src/actions.ts
+++ b/src/actions.ts
@@ -1,3 +1,5 @@
+import { UserType } from './types/data';
+
 const LOGIN_REQUEST = 'LOGIN_REQUEST';
 const LOGIN_SUCCESS = 'LOGIN_SUCCESS';
 const LOGIN_FAILURE = 'LOGIN_FAILURE';
@@ -8,9 +10,6 @@ const USER_DATA_FAILURE = 'USER_DATA_FAILURE';
 const REGISTER_USER_REQUEST = 'REGISTER_USER_REQUEST';
 const REGISTER_USER_SUCCESS = 'REGISTER_USER_SUCCESS';
 const REGISTER_USER_FAILURE = 'REGISTER_USER_FAILURE';
-const MEMBERSHIP_CHARGE_REQUEST = 'MEMBERSHIP_CHARGE_REQUEST';
-const MEMBERSHIP_CHARGE_SUCCESS = 'MEMBERSHIP_CHARGE_SUCCESS';
-const MEMBERSHIP_CHARGE_FAILURE = 'MEMBERSHIP_CHARGE_FAILURE';
 
 function loginRequest() {
   return {
@@ -26,7 +25,7 @@ function loginSuccess(username: string, token: string) {
   };
 }
 
-function loginFailure(loginError) {
+function loginFailure(loginError: string) {
   return {
     type: LOGIN_FAILURE,
     loginError,
@@ -45,14 +44,14 @@ function userDataRequest() {
   };
 }
 
-function userDataSuccess(data) {
+function userDataSuccess(data: UserType) {
   return {
     type: USER_DATA_SUCCESS,
     data,
   };
 }
 
-function userDataFailure(userError) {
+function userDataFailure(userError: string) {
   return {
     type: USER_DATA_FAILURE,
     userError,
@@ -65,38 +64,19 @@ function registerUserRequest() {
   };
 }
 
-function registerUserSuccess(data) {
+function registerUserSuccess(data: UserType) {
   return {
     type: REGISTER_USER_SUCCESS,
     data,
   };
 }
 
-function registerUserFailure(registerError) {
+function registerUserFailure(registerError: Record<string, string>) {
   return {
     type: REGISTER_USER_FAILURE,
     registerError,
   };
 }
-function membershipChargeRequest() {
-  return {
-    type: MEMBERSHIP_CHARGE_REQUEST,
-  };
-}
-
-function membershipChargeSuccess(data) {
-  return {
-    type: MEMBERSHIP_CHARGE_SUCCESS,
-    data,
-  };
-}
-
-function membershipChargeFailure(chargeError) {
-  return {
-    type: MEMBERSHIP_CHARGE_FAILURE,
-    chargeError,
-  };
-}
 
 export {
   /* Login */
@@ -123,11 +103,4 @@ export {
   registerUserSuccess,
   REGISTER_USER_FAILURE,
   registerUserFailure,
-  /* Charge */
-  MEMBERSHIP_CHARGE_REQUEST,
-  membershipChargeRequest,
-  MEMBERSHIP_CHARGE_SUCCESS,
-  membershipChargeSuccess,
-  MEMBERSHIP_CHARGE_FAILURE,
-  membershipChargeFailure,
 };
diff --git a/src/api.ts b/src/api.ts
index 0adf7a7..adc6891 100644
--- a/src/api.ts
+++ b/src/api.ts
@@ -8,9 +8,6 @@ import {
   userDataFailure,
   userDataRequest,
   userDataSuccess,
-  membershipChargeFailure,
-  membershipChargeRequest,
-  membershipChargeSuccess,
 } from './actions';
 import type { UserRegisterFormValues } from './modules/register/useUserRegister';
 import { AppDispatch } from './reduxStore';
@@ -118,41 +115,6 @@ export function requestRegisterUser({ firstName, lastName, email, phoneNumber, p
   };
 }
 
-export function requestMembershipCharge(authToken: string, stripeToken: string, membershipType: string) {
-  return (dispatch: AppDispatch) => {
-    dispatch(membershipChargeRequest());
-
-    return fetchWithTimeout(`${process.env.EXPO_PUBLIC_DUSKEN_API_URL}/api/membership/charge/`, {
-      method: 'POST',
-      headers: {
-        Accept: 'application/json',
-        'Content-Type': 'application/json',
-        Authorization: `Token ${authToken}`,
-      },
-      body: JSON.stringify({
-        stripe_token: stripeToken,
-        membership_type: membershipType,
-        payment_method: 'app',
-      }),
-    })
-      .then((response) => response.json().then((json) => ({ json, response })))
-      .then(({ json, response }) => {
-        if (response.ok === false) {
-          return Promise.reject(json);
-        }
-        return json;
-      })
-      .then(
-        (data) => {
-          dispatch(membershipChargeSuccess(data));
-        },
-        (data) => {
-          dispatch(membershipChargeFailure(data.detail || 'Kunne ikke belaste bankkortet, prøv igjen'));
-        },
-      );
-  };
-}
-
 /** Create a stripe payment sheet. Note that this is not using redux */
 export async function requestStripePaymentSheet(authToken: string, membershipType: string) {
   const body = JSON.stringify({
diff --git a/src/components/FormErrors.tsx b/src/components/FormErrors.tsx
index 1a2cc29..8fcf5ee 100644
--- a/src/components/FormErrors.tsx
+++ b/src/components/FormErrors.tsx
@@ -2,7 +2,8 @@ import { Alert, HStack } from 'native-base';
 import React from 'react';
 import { Text } from 'react-native';
 
-const FormErrors = ({ errors }) => {
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+const FormErrors = ({ errors }: { errors: Record<string, any> }) => {
   if (!Object.keys(errors).length || !['non_field_errors', 'detail'].some((errorField) => errorField in errors)) {
     return null;
   }
diff --git a/src/components/FormInput.tsx b/src/components/FormInput.tsx
index 8baa9db..91e6e81 100644
--- a/src/components/FormInput.tsx
+++ b/src/components/FormInput.tsx
@@ -41,7 +41,7 @@ const FormInput = ({
           />
           {fieldError && (
             <FormControl.ErrorMessage leftIcon={<WarningOutlineIcon size="xs" />}>
-              <Text>{fieldError.message.toString()}</Text>
+              <Text>{fieldError.message?.toString()}</Text>
             </FormControl.ErrorMessage>
           )}
         </FormControl>
diff --git a/src/hooks.tsx b/src/hooks.tsx
index 664f749..479c9e0 100644
--- a/src/hooks.tsx
+++ b/src/hooks.tsx
@@ -6,8 +6,8 @@ import { useDispatch, useSelector, useStore } from 'react-redux';
 
 import type { AppDispatch, AppStore, RootState } from './reduxStore';
 
-export function usePrevious(value) {
-  const ref = useRef();
+export function usePrevious<T>(value: T): T | undefined {
+  const ref = useRef<T>();
 
   // Store current value in ref
   useEffect(() => {
@@ -23,7 +23,7 @@ export const useDeepLinking = () => {
   const { handleURLCallback } = useStripe();
 
   const handleDeepLink = useCallback(
-    async (url) => {
+    async (url: string | null) => {
       if (!url) {
         return;
       }
diff --git a/src/modules/about/About.tsx b/src/modules/about/About.tsx
index 73f1a4a..9742628 100644
--- a/src/modules/about/About.tsx
+++ b/src/modules/about/About.tsx
@@ -21,10 +21,11 @@ const CHATEAU_NEUF_ADDRESS = 'Det Norske Studentersamfund, Slemdalsveien 15, 036
 
 const openFacebook = () => {
   /* Ref: https://stackoverflow.com/questions/4810803/open-facebook-page-from-android-app */
-  const url = Platform.select({
-    ios: 'fb://page/?id=23664032291',
-    android: 'fb://page/23664032291/',
-  });
+  const url =
+    Platform.select({
+      ios: 'fb://page/?id=23664032291',
+      android: 'fb://page/23664032291/',
+    }) || '';
   Linking.canOpenURL(url)
     .then((supported) => {
       if (!supported) {
@@ -36,10 +37,11 @@ const openFacebook = () => {
 };
 
 const openInstagram = () => {
-  const url = Platform.select({
-    ios: 'instagram://user?username=studentersamfundet',
-    android: 'https://instagram.com/_u/studentersamfundet',
-  });
+  const url =
+    Platform.select({
+      ios: 'instagram://user?username=studentersamfundet',
+      android: 'https://instagram.com/_u/studentersamfundet',
+    }) || '';
 
   Linking.canOpenURL(url)
     .then((supported) => {
@@ -52,10 +54,11 @@ const openInstagram = () => {
 };
 
 const openMap = () => {
-  const url = Platform.select({
-    ios: `comgooglemaps://?q=${CHATEAU_NEUF_ADDRESS}`,
-    android: `https://www.google.com/maps/search/?api=1&query=${CHATEAU_NEUF_ADDRESS}`,
-  });
+  const url =
+    Platform.select({
+      ios: `comgooglemaps://?q=${CHATEAU_NEUF_ADDRESS}`,
+      android: `https://www.google.com/maps/search/?api=1&query=${CHATEAU_NEUF_ADDRESS}`,
+    }) || '';
   Linking.canOpenURL(url)
     .then((supported) => {
       if (!supported) {
diff --git a/src/modules/events/EventDetail.tsx b/src/modules/events/EventDetail.tsx
index db5f8e6..f537bee 100644
--- a/src/modules/events/EventDetail.tsx
+++ b/src/modules/events/EventDetail.tsx
@@ -69,10 +69,11 @@ const onFacebookUrlPress = (link: string) => {
   if (matches && matches.length) {
     iosURL = `fb://event/?id=${matches[1]}`;
   }
-  const url = Platform.select({
-    ios: iosURL,
-    android: link,
-  });
+  const url =
+    Platform.select({
+      ios: iosURL,
+      android: link,
+    }) || '';
   Linking.canOpenURL(url)
     .then((supported) => {
       if (!supported) {
diff --git a/src/modules/events/EventList.tsx b/src/modules/events/EventList.tsx
index 9a25af9..6a623e7 100644
--- a/src/modules/events/EventList.tsx
+++ b/src/modules/events/EventList.tsx
@@ -6,6 +6,7 @@ import { Button } from 'react-native-ui-lib';
 import 'moment/locale/nb';
 
 import theme from 'src/theme';
+import { EventType } from 'src/types/data';
 
 import useEventList from './useEventList';
 
@@ -15,7 +16,7 @@ const formatTime = (time: string) => {
   return moment(time).format('llll');
 };
 
-const renderSectionHeader = ({ section }) => (
+const renderSectionHeader = ({ section }: { section: { title: string } }) => (
   <View style={styles.sectionHeader}>
     <Text style={styles.sectionTitle}>{section.title}</Text>
   </View>
@@ -25,7 +26,7 @@ const Header = () => <View style={styles.listHeader} />;
 const EventList = () => {
   const { eventsSectioned, refreshing, handleRefresh, handleLoadMore, showEvent, error, loading } = useEventList();
 
-  const renderItem = ({ item }) => (
+  const renderItem = ({ item }: { item: EventType }) => (
     <TouchableOpacity
       onPress={() => {
         showEvent(item);
@@ -77,7 +78,7 @@ const EventList = () => {
       sections={eventsSectioned}
       renderItem={renderItem}
       renderSectionHeader={renderSectionHeader}
-      keyExtractor={(item) => item.id}
+      keyExtractor={(item: EventType) => item.id}
       refreshing={refreshing}
       onRefresh={handleRefresh}
       onEndReached={handleLoadMore}
diff --git a/src/modules/events/useEventList.tsx b/src/modules/events/useEventList.tsx
index fb68ea6..3b410f1 100644
--- a/src/modules/events/useEventList.tsx
+++ b/src/modules/events/useEventList.tsx
@@ -8,25 +8,28 @@ import { fetchWithTimeout } from 'src/utils';
 
 moment.locale('nb');
 
-const formatDate = (time) => {
+const formatDate = (time: string) => {
   const m = moment(time);
   return moment().year() === m.year() ? m.format('dddd D. MMMM') : m.format('ll');
 };
-
+type SectionedEvents = {
+  data: EventType[];
+  title: string;
+};
 /* Ref: https://medium.com/react-native-development/how-to-use-the-flatlist-component-react-native-basics-92c482816fe6 */
 const useEventList = () => {
   const { navigate } = useNavigation();
 
   const [loading, setLoading] = useState(false);
-  const [events, setEvents] = useState([]);
-  const [eventsSectioned, setEventsSectioned] = useState([]);
+  const [events, setEvents] = useState<EventType[]>([]);
+  const [eventsSectioned, setEventsSectioned] = useState<SectionedEvents[]>([]);
   const [page, setPage] = useState(1);
   const [totalPages, setTotalPages] = useState(0);
-  const [error, setError] = useState(null);
+  const [error, setError] = useState<unknown>(null);
   const [refreshing, setRefreshing] = useState(false);
 
-  const toSectionFormat = (freshEvents) => {
-    const sectioned = {};
+  const toSectionFormat = (freshEvents: EventType[]) => {
+    const sectioned: Record<string, EventType[]> = {};
     freshEvents.forEach((event) => {
       const title = formatDate(event.start_time);
       if (title in sectioned) {
@@ -62,7 +65,7 @@ const useEventList = () => {
     let eventData;
     try {
       const res = await fetchWithTimeout(url);
-      setTotalPages(parseInt(res.headers.get('x-wp-totalpages'), 10));
+      setTotalPages(parseInt(res.headers.get('x-wp-totalpages') || '0', 10));
       eventData = await res.json();
     } catch (err) {
       setError(err);
diff --git a/src/modules/membership/Proof.tsx b/src/modules/membership/Proof.tsx
index 0fc615c..16b27b5 100644
--- a/src/modules/membership/Proof.tsx
+++ b/src/modules/membership/Proof.tsx
@@ -75,14 +75,14 @@ interface PurchaseButtonProps {
   paymentLoading: boolean;
   isLoadingMembershipType: boolean;
   membershipPrice: number;
-  onChargePress: () => void;
+  onPurchasePress: () => void;
 }
 
 const PurchaseButton = ({
   user,
   paymentLoading,
   isLoadingMembershipType,
-  onChargePress,
+  onPurchasePress,
   membershipPrice,
 }: PurchaseButtonProps) => {
   if (user.is_member) {
@@ -93,7 +93,7 @@ const PurchaseButton = ({
     <View>
       {paymentLoading && <ActivityIndicator color={theme.colors.neufOrange} />}
       <Button
-        onPress={onChargePress}
+        onPress={onPurchasePress}
         fullWidth
         disabled={paymentLoading || isLoadingMembershipType}
         style={styles.purchaseButton}
@@ -128,18 +128,6 @@ const Logo = ({ user }: { user: UserType }) => {
   );
 };
 
-const ChargeError = ({ chargeError }) => {
-  if (!chargeError) {
-    return null;
-  }
-
-  return (
-    <View>
-      <Text style={styles.errorMessage}>{chargeError}</Text>
-    </View>
-  );
-};
-
 const MembershipName = ({ user }: { user: UserType }) => {
   let name = `${user.first_name} ${user.last_name}`;
   if (name === ' ') {
@@ -160,16 +148,7 @@ interface ProofProps {
 const Proof = ({ onLogoutPress, fetchUser, isFetchingUserData }: ProofProps) => {
   const CONFETTI_TIMEOUT = 15000;
   const confettiRef = useRef<Confetti>(null);
-  const {
-    chargeError,
-    paymentLoading,
-    isLoadingMembershipType,
-    onChargePress,
-    membershipPrice,
-    toast,
-    setToast,
-    user,
-  } = useProof({
+  const { paymentLoading, isLoadingMembershipType, onPurchasePress, membershipPrice, toast, setToast, user } = useProof({
     fetchUser,
   });
 
@@ -183,7 +162,7 @@ const Proof = ({ onLogoutPress, fetchUser, isFetchingUserData }: ProofProps) =>
   });
 
   const onMembershipPress = () => {
-    confettiRef.current.startConfetti();
+    confettiRef.current?.startConfetti();
     setTimeout(() => {
       if (confettiRef && confettiRef.current) {
         confettiRef.current.stopConfetti();
@@ -208,13 +187,12 @@ const Proof = ({ onLogoutPress, fetchUser, isFetchingUserData }: ProofProps) =>
             <MembershipName user={user} />
             <Logo user={user} />
             <MembershipStatus user={user} onMembershipPress={onMembershipPress} />
-            <ChargeError chargeError={chargeError} />
             <PurchaseButton
               user={user}
               paymentLoading={paymentLoading}
               isLoadingMembershipType={isLoadingMembershipType}
               membershipPrice={membershipPrice}
-              onChargePress={onChargePress}
+              onPurchasePress={onPurchasePress}
             />
             <MembershipValidTo user={user} />
           </View>
diff --git a/src/modules/membership/useMembership.tsx b/src/modules/membership/useMembership.tsx
index 1497ca2..2b8114a 100644
--- a/src/modules/membership/useMembership.tsx
+++ b/src/modules/membership/useMembership.tsx
@@ -10,10 +10,8 @@ const useMembership = () => {
   const dispatch = useAppDispatch();
   const isAuthenticated = useAppSelector((store) => store.isAuthenticated);
   const isFetchingUserData = useAppSelector((store) => store.isFetchingUserData);
-  const lastOrder = useAppSelector((store) => store.lastOrder);
   const userToken = useAppSelector((store) => store.userToken);
   const prevUserToken = usePrevious(userToken);
-  const prevLastOrder = usePrevious(lastOrder);
 
   const onLogoutPress = () => {
     dispatch(logout());
@@ -22,23 +20,19 @@ const useMembership = () => {
   const onRegisterPress = () => navigation.navigate('UserStack', { screen: 'UserRegister' });
   const onLoginPress = () => navigation.navigate('UserStack', { screen: 'Login' });
   const fetchUser = useCallback(() => {
-    dispatch(requestUserData(userToken));
+    dispatch(requestUserData(userToken || ''));
   }, [dispatch, userToken]);
 
   useEffect(() => {
     if (userToken !== prevUserToken && userToken) {
       fetchUser();
     }
-    if (prevLastOrder !== lastOrder && userToken) {
-      fetchUser();
-    }
-  }, [userToken, prevUserToken, lastOrder, prevLastOrder, fetchUser]);
+  }, [userToken, prevUserToken, fetchUser]);
 
   return {
     isAuthenticated,
     isFetchingUserData,
     userToken,
-    lastOrder,
     onLogoutPress,
     onRegisterPress,
     onLoginPress,
diff --git a/src/modules/membership/useProof.tsx b/src/modules/membership/useProof.tsx
index 45f49a5..b7b102b 100644
--- a/src/modules/membership/useProof.tsx
+++ b/src/modules/membership/useProof.tsx
@@ -5,6 +5,7 @@ import { useEffect, useState } from 'react';
 
 import { requestStripePaymentSheet } from 'src/api';
 import { useAppSelector } from 'src/hooks';
+import { ToastProps } from 'src/types/toast';
 
 const PROOF_QUERY = gql`
   {
@@ -15,16 +16,13 @@ const PROOF_QUERY = gql`
   }
 `;
 
-interface ToastProps {
-  message: string;
-  visible: boolean;
-  preset: 'failure' | 'success';
+interface UseProofProps {
+  fetchUser: () => void;
 }
 
-const useProof = ({ fetchUser }) => {
+const useProof = ({ fetchUser }: UseProofProps) => {
   const user = useAppSelector((state) => state.user);
   const userToken = useAppSelector((state) => state.userToken);
-  const chargeError = useAppSelector((state) => state.chargeError);
   const { data, loading } = useQuery(PROOF_QUERY);
   const { initPaymentSheet, presentPaymentSheet } = useStripe();
   const [paymentLoading, setPaymentLoading] = useState(false);
@@ -81,10 +79,9 @@ const useProof = ({ fetchUser }) => {
 
   const membershipPrice = data?.membershipTypes?.[0]?.price;
   return {
-    chargeError: chargeError || '',
     isLoadingMembershipType: loading,
     membershipPrice: membershipPrice ? membershipPrice / 100 : 0,
-    onChargePress: openPaymentSheet,
+    onPurchasePress: openPaymentSheet,
     paymentLoading,
     toast,
     setToast,
diff --git a/src/modules/register/useUserRegister.tsx b/src/modules/register/useUserRegister.tsx
index ac7d4c9..1ed4a1f 100644
--- a/src/modules/register/useUserRegister.tsx
+++ b/src/modules/register/useUserRegister.tsx
@@ -4,6 +4,7 @@ import { useForm } from 'react-hook-form';
 
 import { requestRegisterUser } from 'src/api';
 import { useAppDispatch, useAppSelector, usePrevious } from 'src/hooks';
+import { ToastProps } from 'src/types/toast';
 
 export interface UserRegisterFormValues {
   firstName: string;
@@ -19,7 +20,7 @@ const useUserRegister = () => {
   const isAuthenticated = useAppSelector((store) => store.isAuthenticated);
   const isRegisteringUser = useAppSelector((store) => store.isRegisteringUser);
   const registerError = useAppSelector((store) => store.registerError) || {};
-  const [toast, setToast] = useState(null);
+  const [toast, setToast] = useState<ToastProps | null>(null);
 
   const isAuthenticatedPrev = usePrevious(isAuthenticated);
 
diff --git a/src/reducers.ts b/src/reducers.ts
index e7674b4..2471717 100644
--- a/src/reducers.ts
+++ b/src/reducers.ts
@@ -9,9 +9,6 @@ import {
   REGISTER_USER_REQUEST,
   REGISTER_USER_FAILURE,
   REGISTER_USER_SUCCESS,
-  MEMBERSHIP_CHARGE_REQUEST,
-  MEMBERSHIP_CHARGE_FAILURE,
-  MEMBERSHIP_CHARGE_SUCCESS,
 } from './actions';
 import type { UserType } from './types/data';
 import { snakeToCamelCase } from './utils';
@@ -21,15 +18,11 @@ interface RootState {
   isLoggingIn: boolean;
   isFetchingUserData: boolean;
   isRegisteringUser: boolean;
-  isChargingMembership: boolean;
   userToken: string | null;
   user: UserType | null;
-  // FIXME: Type rest
-  loginError: unknown | null;
-  userError: unknown | null;
-  registerError: unknown | null;
-  chargeError: unknown | null;
-  lastOrder: unknown | null;
+  loginError: Record<string, string> | null;
+  userError: Record<string, string> | null;
+  registerError: Record<string, string> | null;
 }
 
 const initialState: RootState = {
@@ -37,26 +30,24 @@ const initialState: RootState = {
   isLoggingIn: false,
   isFetchingUserData: false,
   isRegisteringUser: false,
-  isChargingMembership: false,
   userToken: null,
   user: null,
   loginError: null,
   userError: null,
   registerError: null,
-  chargeError: null,
-  lastOrder: null,
 };
 
-function formatErrors(errs) {
-  const errors = {};
+function formatErrors(errs: Record<string, string | string[]>) {
+  const errors: Record<string, string> = {};
   Object.entries(errs).forEach(([key, value]) => {
     errors[snakeToCamelCase(key)] = Array.isArray(value) ? value.join('\n') : value;
   });
   return errors;
 }
 
-// eslint-disable-next-line @typescript-eslint/default-param-last
-export default function duskenApp(state = initialState, action) {
+// FIXME: refactor using redux slices
+// eslint-disable-next-line @typescript-eslint/default-param-last, @typescript-eslint/no-explicit-any
+export default function duskenApp(state = initialState, action: any) {
   switch (action.type) {
     /* Login */
     case LOGIN_REQUEST:
@@ -97,16 +88,6 @@ export default function duskenApp(state = initialState, action) {
 
       return { ...state, isRegisteringUser: false, isAuthenticated: true, user: userData, userToken: token };
 
-    /* Membership charge */
-    case MEMBERSHIP_CHARGE_REQUEST:
-      return { ...state, isChargingMembership: true, chargeError: null };
-
-    case MEMBERSHIP_CHARGE_FAILURE:
-      return { ...state, isChargingMembership: false, chargeError: action.chargeError };
-
-    case MEMBERSHIP_CHARGE_SUCCESS:
-      return { ...state, isChargingMembership: false, lastOrder: action.data };
-
     default:
       return state;
   }
diff --git a/src/reduxStore.ts b/src/reduxStore.ts
index 6cab4dd..a3eaa55 100644
--- a/src/reduxStore.ts
+++ b/src/reduxStore.ts
@@ -8,7 +8,7 @@ import rootReducer from './reducers';
 const persistConfig = {
   key: 'root',
   storage: AsyncStorage,
-  blacklist: ['isLoggingIn', 'isFetchingUserData', 'isRegisteringUser', 'isChargingMembership', 'loginError'],
+  blacklist: ['isLoggingIn', 'isFetchingUserData', 'isRegisteringUser', 'loginError'],
 };
 
 const persistedReducer = persistReducer(persistConfig, rootReducer);
diff --git a/src/types/data.ts b/src/types/data.ts
index 1183ff0..2de790a 100644
--- a/src/types/data.ts
+++ b/src/types/data.ts
@@ -1,4 +1,5 @@
 export interface EventType {
+  id: string;
   start_time: string;
   end_time: string;
   content: {
diff --git a/src/types/toast.ts b/src/types/toast.ts
new file mode 100644
index 0000000..9da90ad
--- /dev/null
+++ b/src/types/toast.ts
@@ -0,0 +1,5 @@
+export interface ToastProps {
+  message: string;
+  visible: boolean;
+  preset: 'failure' | 'success';
+}
diff --git a/src/utils.ts b/src/utils.ts
index 728fba3..a4ff441 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -1,4 +1,4 @@
-export function snakeToCamelCase(val: string) {
+export function snakeToCamelCase(val: string): string {
   return val.replace(/_([a-z])/g, (g) => g[1].toUpperCase());
 }
 
diff --git a/tsconfig.json b/tsconfig.json
index a9f72b2..29eb181 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
     "baseUrl": "./",
+    "strict": true
   },
   "extends": "expo/tsconfig.base"
 }