diff --git a/libs/common/src/lib/interfaces/lookup-item.interface.ts b/libs/common/src/lib/interfaces/lookup-item.interface.ts
index fa91ed690..6cedeca09 100644
--- a/libs/common/src/lib/interfaces/lookup-item.interface.ts
+++ b/libs/common/src/lib/interfaces/lookup-item.interface.ts
@@ -7,7 +7,7 @@ export interface LookupItem {
   assetSubClass: AssetSubClass;
   currency: string;
   dataProviderInfo: DataProviderInfo;
-  dataSource: DataSource;
+  dataSource: DataSource | null;
   name: string;
   symbol: string;
 }
diff --git a/libs/ui/src/lib/accounts-table/accounts-table.component.ts b/libs/ui/src/lib/accounts-table/accounts-table.component.ts
index 21300fdcc..0c0cab070 100644
--- a/libs/ui/src/lib/accounts-table/accounts-table.component.ts
+++ b/libs/ui/src/lib/accounts-table/accounts-table.component.ts
@@ -77,7 +77,7 @@ export class GfAccountsTableComponent implements OnChanges, OnDestroy {
   @ViewChild(MatSort) sort: MatSort;
 
   public dataSource = new MatTableDataSource<Account>();
-  public displayedColumns = [];
+  public displayedColumns: string[] = [];
   public isLoading = true;
   public routeQueryParams: Subscription;
 
diff --git a/libs/ui/src/lib/activities-table/activities-table.component.stories.ts b/libs/ui/src/lib/activities-table/activities-table.component.stories.ts
index e7a2ba819..25463e576 100644
--- a/libs/ui/src/lib/activities-table/activities-table.component.stories.ts
+++ b/libs/ui/src/lib/activities-table/activities-table.component.stories.ts
@@ -59,7 +59,7 @@ const activities: Activity[] = [
     SymbolProfile: {
       assetClass: 'EQUITY',
       assetSubClass: 'ETF',
-      comment: null,
+      comment: undefined,
       countries: [],
       createdAt: new Date('2021-06-06T16:12:20.982Z'),
       currency: 'USD',
@@ -74,12 +74,12 @@ const activities: Activity[] = [
       isin: 'US9220427424',
       name: 'Vanguard Total World Stock Index Fund ETF Shares',
       updatedAt: new Date('2025-10-01T20:09:39.500Z'),
-      scraperConfiguration: null,
+      scraperConfiguration: undefined,
       sectors: [],
       symbol: 'VT',
       symbolMapping: {},
       url: 'https://www.vanguard.com',
-      userId: null,
+      userId: undefined,
       activitiesCount: 267,
       dateOfFirstActivity: new Date('2018-05-31T16:00:00.000Z')
     },
@@ -126,7 +126,7 @@ const activities: Activity[] = [
     SymbolProfile: {
       assetClass: 'EQUITY',
       assetSubClass: 'ETF',
-      comment: null,
+      comment: undefined,
       countries: [],
       createdAt: new Date('2021-06-06T16:12:20.982Z'),
       currency: 'USD',
@@ -141,12 +141,12 @@ const activities: Activity[] = [
       isin: 'US9220427424',
       name: 'Vanguard Total World Stock Index Fund ETF Shares',
       updatedAt: new Date('2025-10-01T20:09:39.500Z'),
-      scraperConfiguration: null,
+      scraperConfiguration: undefined,
       sectors: [],
       symbol: 'VT',
       symbolMapping: {},
       url: 'https://www.vanguard.com',
-      userId: null,
+      userId: undefined,
       activitiesCount: 267,
       dateOfFirstActivity: new Date('2018-05-31T16:00:00.000Z')
     },
@@ -193,7 +193,7 @@ const activities: Activity[] = [
     SymbolProfile: {
       assetClass: 'LIQUIDITY',
       assetSubClass: 'CRYPTOCURRENCY',
-      comment: null,
+      comment: undefined,
       countries: [],
       createdAt: new Date('2024-03-12T15:15:21.217Z'),
       currency: 'USD',
@@ -208,12 +208,12 @@ const activities: Activity[] = [
       isin: 'CA4639181029',
       name: 'iShares Bitcoin Trust',
       updatedAt: new Date('2025-09-29T03:14:07.742Z'),
-      scraperConfiguration: null,
+      scraperConfiguration: undefined,
       sectors: [],
       symbol: 'IBIT',
       symbolMapping: {},
       url: 'https://www.ishares.com',
-      userId: null,
+      userId: undefined,
       activitiesCount: 6,
       dateOfFirstActivity: new Date('2024-01-01T08:00:00.000Z')
     },
@@ -280,7 +280,7 @@ const activities: Activity[] = [
       symbol: 'BNDW',
       symbolMapping: {},
       url: 'https://vanguard.com',
-      userId: null,
+      userId: undefined,
       activitiesCount: 38,
       dateOfFirstActivity: new Date('2022-04-13T20:05:48.742Z')
     },
@@ -327,7 +327,7 @@ const activities: Activity[] = [
     SymbolProfile: {
       assetClass: 'EQUITY',
       assetSubClass: 'ETF',
-      comment: null,
+      comment: undefined,
       countries: [],
       createdAt: new Date('2021-06-06T16:12:20.982Z'),
       currency: 'USD',
@@ -342,12 +342,12 @@ const activities: Activity[] = [
       isin: 'US9220427424',
       name: 'Vanguard Total World Stock Index Fund ETF Shares',
       updatedAt: new Date('2025-10-01T20:09:39.500Z'),
-      scraperConfiguration: null,
+      scraperConfiguration: undefined,
       sectors: [],
       symbol: 'VT',
       symbolMapping: {},
       url: 'https://www.vanguard.com',
-      userId: null,
+      userId: undefined,
       activitiesCount: 267,
       dateOfFirstActivity: new Date('2018-05-31T16:00:00.000Z')
     },
diff --git a/libs/ui/src/lib/fire-calculator/fire-calculator.component.ts b/libs/ui/src/lib/fire-calculator/fire-calculator.component.ts
index 7461f6729..79dc2fbbd 100644
--- a/libs/ui/src/lib/fire-calculator/fire-calculator.component.ts
+++ b/libs/ui/src/lib/fire-calculator/fire-calculator.component.ts
@@ -100,10 +100,15 @@ export class GfFireCalculatorComponent implements OnChanges, OnDestroy {
   @ViewChild('chartCanvas') chartCanvas: ElementRef<HTMLCanvasElement>;
 
   public calculatorForm = this.formBuilder.group({
+    // @ts-ignore
     annualInterestRate: new FormControl<number>(undefined),
+    // @ts-ignore
     paymentPerPeriod: new FormControl<number>(undefined),
+    // @ts-ignore
     principalInvestmentAmount: new FormControl<number>(undefined),
+    // @ts-ignore
     projectedTotalAmount: new FormControl<number>(undefined),
+    // @ts-ignore
     retirementDate: new FormControl<Date>(undefined)
   });
   public chart: Chart<'bar'>;
@@ -150,25 +155,25 @@ export class GfFireCalculatorComponent implements OnChanges, OnDestroy {
 
     this.calculatorForm
       .get('annualInterestRate')
-      .valueChanges.pipe(debounceTime(500), takeUntil(this.unsubscribeSubject))
+      ?.valueChanges.pipe(debounceTime(500), takeUntil(this.unsubscribeSubject))
       .subscribe((annualInterestRate) => {
         this.annualInterestRateChanged.emit(annualInterestRate);
       });
     this.calculatorForm
       .get('paymentPerPeriod')
-      .valueChanges.pipe(debounceTime(500), takeUntil(this.unsubscribeSubject))
+      ?.valueChanges.pipe(debounceTime(500), takeUntil(this.unsubscribeSubject))
       .subscribe((savingsRate) => {
         this.savingsRateChanged.emit(savingsRate);
       });
     this.calculatorForm
       .get('projectedTotalAmount')
-      .valueChanges.pipe(debounceTime(500), takeUntil(this.unsubscribeSubject))
+      ?.valueChanges.pipe(debounceTime(500), takeUntil(this.unsubscribeSubject))
       .subscribe((projectedTotalAmount) => {
         this.projectedTotalAmountChanged.emit(projectedTotalAmount);
       });
     this.calculatorForm
       .get('retirementDate')
-      .valueChanges.pipe(debounceTime(500), takeUntil(this.unsubscribeSubject))
+      ?.valueChanges.pipe(debounceTime(500), takeUntil(this.unsubscribeSubject))
       .subscribe((retirementDate) => {
         this.retirementDateChanged.emit(retirementDate);
       });
@@ -196,11 +201,11 @@ export class GfFireCalculatorComponent implements OnChanges, OnDestroy {
         this.calculatorForm.patchValue(
           {
             annualInterestRate:
-              this.calculatorForm.get('annualInterestRate').value,
+              this.calculatorForm.get('annualInterestRate')?.value,
             paymentPerPeriod: this.getPMT(),
             principalInvestmentAmount: this.calculatorForm.get(
               'principalInvestmentAmount'
-            ).value,
+            )?.value,
             projectedTotalAmount:
               Math.round(this.getProjectedTotalAmount()) || 0,
             retirementDate:
@@ -210,7 +215,7 @@ export class GfFireCalculatorComponent implements OnChanges, OnDestroy {
             emitEvent: false
           }
         );
-        this.calculatorForm.get('principalInvestmentAmount').disable();
+        this.calculatorForm.get('principalInvestmentAmount')?.disable();
 
         this.changeDetectorRef.markForCheck();
       });
@@ -219,34 +224,36 @@ export class GfFireCalculatorComponent implements OnChanges, OnDestroy {
     if (this.hasPermissionToUpdateUserSettings === true) {
       this.calculatorForm
         .get('annualInterestRate')
-        .enable({ emitEvent: false });
-      this.calculatorForm.get('paymentPerPeriod').enable({ emitEvent: false });
+        ?.enable({ emitEvent: false });
+      this.calculatorForm.get('paymentPerPeriod')?.enable({ emitEvent: false });
       this.calculatorForm
         .get('projectedTotalAmount')
-        .enable({ emitEvent: false });
+        ?.enable({ emitEvent: false });
     } else {
       this.calculatorForm
         .get('annualInterestRate')
-        .disable({ emitEvent: false });
-      this.calculatorForm.get('paymentPerPeriod').disable({ emitEvent: false });
+        ?.disable({ emitEvent: false });
+      this.calculatorForm
+        .get('paymentPerPeriod')
+        ?.disable({ emitEvent: false });
       this.calculatorForm
         .get('projectedTotalAmount')
-        .disable({ emitEvent: false });
+        ?.disable({ emitEvent: false });
     }
 
-    this.calculatorForm.get('retirementDate').disable({ emitEvent: false });
+    this.calculatorForm.get('retirementDate')?.disable({ emitEvent: false });
   }
 
   public setMonthAndYear(
     normalizedMonthAndYear: Date,
     datepicker: MatDatepicker<Date>
   ) {
-    const retirementDate = this.calculatorForm.get('retirementDate').value;
+    const retirementDate = this.calculatorForm.get('retirementDate')!.value;
     const newRetirementDate = setMonth(
       setYear(retirementDate, normalizedMonthAndYear.getFullYear()),
       normalizedMonthAndYear.getMonth()
     );
-    this.calculatorForm.get('retirementDate').setValue(newRetirementDate);
+    this.calculatorForm.get('retirementDate')?.setValue(newRetirementDate);
     datepicker.close();
   }
 
@@ -360,6 +367,7 @@ export class GfFireCalculatorComponent implements OnChanges, OnDestroy {
 
     // Calculate retirement date
     // if we want to retire at month x, we need the projectedTotalAmount at month x-1
+    // @ts-ignore
     const lastPeriodDate = sub(this.getRetirementDate(), { months: 1 });
     const yearsToRetire = lastPeriodDate.getFullYear() - currentYear;
 
@@ -426,12 +434,12 @@ export class GfFireCalculatorComponent implements OnChanges, OnDestroy {
   }
 
   private getPeriodsToRetire(): number {
-    if (this.calculatorForm.get('projectedTotalAmount').value) {
+    if (this.calculatorForm.get('projectedTotalAmount')?.value) {
       let periods = this.fireCalculatorService.calculatePeriodsToRetire({
         P: this.getP(),
         PMT: this.getPMT(),
         r: this.getR(),
-        totalAmount: this.calculatorForm.get('projectedTotalAmount').value
+        totalAmount: this.calculatorForm.get('projectedTotalAmount')!.value
       });
 
       if (periods === Infinity) {
@@ -452,13 +460,13 @@ export class GfFireCalculatorComponent implements OnChanges, OnDestroy {
     }
   }
 
-  private getPMT() {
-    return this.calculatorForm.get('paymentPerPeriod').value;
+  private getPMT(): number {
+    return this.calculatorForm.get('paymentPerPeriod')!.value;
   }
 
   private getProjectedTotalAmount() {
-    if (this.calculatorForm.get('projectedTotalAmount').value) {
-      return this.calculatorForm.get('projectedTotalAmount').value;
+    if (this.calculatorForm.get('projectedTotalAmount')?.value) {
+      return this.calculatorForm.get('projectedTotalAmount')!.value;
     }
 
     const { totalAmount } =
@@ -473,10 +481,10 @@ export class GfFireCalculatorComponent implements OnChanges, OnDestroy {
   }
 
   private getR() {
-    return this.calculatorForm.get('annualInterestRate').value / 100;
+    return this.calculatorForm.get('annualInterestRate')!.value / 100;
   }
 
-  private getRetirementDate(): Date {
+  private getRetirementDate(): Date | undefined {
     if (this.periodsToRetire === Number.MAX_SAFE_INTEGER) {
       return undefined;
     }
diff --git a/libs/ui/src/lib/holdings-table/holdings-table.component.ts b/libs/ui/src/lib/holdings-table/holdings-table.component.ts
index f408f7d9b..3abb9903e 100644
--- a/libs/ui/src/lib/holdings-table/holdings-table.component.ts
+++ b/libs/ui/src/lib/holdings-table/holdings-table.component.ts
@@ -62,7 +62,7 @@ export class GfHoldingsTableComponent implements OnChanges, OnDestroy {
   @ViewChild(MatSort) sort: MatSort;
 
   public dataSource = new MatTableDataSource<PortfolioPosition>();
-  public displayedColumns = [];
+  public displayedColumns: string[] = [];
   public ignoreAssetSubClasses = [AssetSubClass.CASH];
   public isLoading = true;
   public routeQueryParams: Subscription;
diff --git a/libs/ui/src/lib/line-chart/line-chart.component.ts b/libs/ui/src/lib/line-chart/line-chart.component.ts
index dd972bc5a..f74fb48a1 100644
--- a/libs/ui/src/lib/line-chart/line-chart.component.ts
+++ b/libs/ui/src/lib/line-chart/line-chart.component.ts
@@ -316,7 +316,9 @@ export class GfLineChartComponent
       },
       duration: delayBetweenPoints,
       easing: 'linear',
+      // @ts-ignore
       from: NaN,
+      // @ts-ignore
       type: 'number'
     };
   }
diff --git a/libs/ui/src/lib/mocks/holdings.ts b/libs/ui/src/lib/mocks/holdings.ts
index 3f57af884..f6ce036c8 100644
--- a/libs/ui/src/lib/mocks/holdings.ts
+++ b/libs/ui/src/lib/mocks/holdings.ts
@@ -158,7 +158,7 @@ export const holdings: PortfolioPosition[] = [
     sectors: [],
     symbol: 'bitcoin',
     tags: [],
-    url: null,
+    url: undefined,
     valueInBaseCurrency: 54666.7898248
   },
   {
diff --git a/libs/ui/src/lib/no-transactions-info/no-transactions-info.component.ts b/libs/ui/src/lib/no-transactions-info/no-transactions-info.component.ts
index 8691dc998..9ca91d111 100644
--- a/libs/ui/src/lib/no-transactions-info/no-transactions-info.component.ts
+++ b/libs/ui/src/lib/no-transactions-info/no-transactions-info.component.ts
@@ -24,5 +24,5 @@ export class GfNoTransactionsInfoComponent {
   @HostBinding('class.has-border') @Input() hasBorder = true;
 
   public routerLinkPortfolioActivities =
-    internalRoutes.portfolio.subRoutes.activities.routerLink;
+    internalRoutes.portfolio.subRoutes?.activities.routerLink;
 }
diff --git a/libs/ui/src/lib/notifications/alert-dialog/alert-dialog.component.ts b/libs/ui/src/lib/notifications/alert-dialog/alert-dialog.component.ts
index 33d26c493..acd63d995 100644
--- a/libs/ui/src/lib/notifications/alert-dialog/alert-dialog.component.ts
+++ b/libs/ui/src/lib/notifications/alert-dialog/alert-dialog.component.ts
@@ -11,8 +11,8 @@ import { AlertDialogParams } from './interfaces/interfaces';
   templateUrl: './alert-dialog.html'
 })
 export class GfAlertDialogComponent {
-  public discardLabel: string;
-  public message: string;
+  public discardLabel?: string;
+  public message?: string;
   public title: string;
 
   public constructor(public dialogRef: MatDialogRef<GfAlertDialogComponent>) {}
diff --git a/libs/ui/src/lib/notifications/confirmation-dialog/confirmation-dialog.component.ts b/libs/ui/src/lib/notifications/confirmation-dialog/confirmation-dialog.component.ts
index a3bc053ee..ccbb3e737 100644
--- a/libs/ui/src/lib/notifications/confirmation-dialog/confirmation-dialog.component.ts
+++ b/libs/ui/src/lib/notifications/confirmation-dialog/confirmation-dialog.component.ts
@@ -13,10 +13,10 @@ import { ConfirmDialogParams } from './interfaces/interfaces';
   templateUrl: './confirmation-dialog.html'
 })
 export class GfConfirmationDialogComponent {
-  public confirmLabel: string;
+  public confirmLabel?: string;
   public confirmType: ConfirmationDialogType;
-  public discardLabel: string;
-  public message: string;
+  public discardLabel?: string;
+  public message?: string;
   public title: string;
 
   public constructor(
diff --git a/libs/ui/src/lib/notifications/prompt-dialog/prompt-dialog.component.ts b/libs/ui/src/lib/notifications/prompt-dialog/prompt-dialog.component.ts
index 6ea68d863..f62116c83 100644
--- a/libs/ui/src/lib/notifications/prompt-dialog/prompt-dialog.component.ts
+++ b/libs/ui/src/lib/notifications/prompt-dialog/prompt-dialog.component.ts
@@ -18,25 +18,25 @@ import { MatInputModule } from '@angular/material/input';
 })
 export class GfPromptDialogComponent {
   public confirmLabel: string;
-  public defaultValue: string;
+  public defaultValue?: string;
   public discardLabel: string;
   public formControl = new FormControl('');
   public title: string;
-  public valueLabel: string;
+  public valueLabel?: string;
 
   public constructor(public dialogRef: MatDialogRef<GfPromptDialogComponent>) {}
 
   public initialize(aParams: {
-    confirmLabel?: string;
+    confirmLabel: string;
     defaultValue?: string;
-    discardLabel?: string;
+    discardLabel: string;
     title: string;
     valueLabel?: string;
   }) {
     this.confirmLabel = aParams.confirmLabel;
     this.defaultValue = aParams.defaultValue;
     this.discardLabel = aParams.discardLabel;
-    this.formControl.setValue(aParams.defaultValue);
+    this.formControl.setValue(aParams.defaultValue ?? null);
     this.title = aParams.title;
     this.valueLabel = aParams.valueLabel;
   }
diff --git a/libs/ui/src/lib/portfolio-filter-form/portfolio-filter-form.component.ts b/libs/ui/src/lib/portfolio-filter-form/portfolio-filter-form.component.ts
index afbe5af4e..b83a43aa8 100644
--- a/libs/ui/src/lib/portfolio-filter-form/portfolio-filter-form.component.ts
+++ b/libs/ui/src/lib/portfolio-filter-form/portfolio-filter-form.component.ts
@@ -70,10 +70,10 @@ export class GfPortfolioFilterFormComponent
     private formBuilder: FormBuilder
   ) {
     this.filterForm = this.formBuilder.group({
-      account: new FormControl<string>(null),
-      assetClass: new FormControl<string>(null),
-      holding: new FormControl<PortfolioPosition>(null),
-      tag: new FormControl<string>(null)
+      account: new FormControl<string | null>(null),
+      assetClass: new FormControl<string | null>(null),
+      holding: new FormControl<PortfolioPosition | null>(null),
+      tag: new FormControl<string | null>(null)
     });
   }
 
diff --git a/libs/ui/src/lib/portfolio-proportion-chart/portfolio-proportion-chart.component.ts b/libs/ui/src/lib/portfolio-proportion-chart/portfolio-proportion-chart.component.ts
index 7d0203e9c..1cd9f48e5 100644
--- a/libs/ui/src/lib/portfolio-proportion-chart/portfolio-proportion-chart.component.ts
+++ b/libs/ui/src/lib/portfolio-proportion-chart/portfolio-proportion-chart.component.ts
@@ -140,16 +140,18 @@ export class GfPortfolioProportionChartComponent
 
             if (
               chartData[this.data[symbol][this.keys[0]].toUpperCase()]
-                .subCategory[this.data[symbol][this.keys[1]]]
+                ?.subCategory?.[this.data[symbol][this.keys[1]]]
             ) {
+              // @ts-ignore
               chartData[
                 this.data[symbol][this.keys[0]].toUpperCase()
               ].subCategory[this.data[symbol][this.keys[1]]].value = chartData[
                 this.data[symbol][this.keys[0]].toUpperCase()
-              ].subCategory[this.data[symbol][this.keys[1]]].value.plus(
+              ].subCategory?.[this.data[symbol][this.keys[1]]].value.plus(
                 this.data[symbol].value || 0
               );
             } else {
+              // @ts-ignore
               chartData[
                 this.data[symbol][this.keys[0]].toUpperCase()
               ].subCategory[this.data[symbol][this.keys[1]] ?? UNKNOWN_KEY] = {
@@ -278,12 +280,14 @@ export class GfPortfolioProportionChartComponent
 
       Object.keys(item.subCategory ?? {}).forEach((subCategory) => {
         if (item.name === UNKNOWN_KEY) {
+          // @ts-ignore
           backgroundColorSubCategory.push(item.color);
         } else {
           backgroundColorSubCategory.push(
             Color(item.color).lighten(lightnessRatio).hex()
           );
         }
+        // @ts-ignore
         dataSubCategory.push(item.subCategory[subCategory].value.toNumber());
         labelSubCategory.push(subCategory);
 
diff --git a/libs/ui/src/lib/services/admin.service.ts b/libs/ui/src/lib/services/admin.service.ts
index 145f134e3..a10798401 100644
--- a/libs/ui/src/lib/services/admin.service.ts
+++ b/libs/ui/src/lib/services/admin.service.ts
@@ -132,7 +132,7 @@ export class AdminService {
   public fetchJobs({ status }: { status?: JobStatus[] }) {
     let params = new HttpParams();
 
-    if (status?.length > 0) {
+    if (status && status.length > 0) {
       params = params.append('status', status.join(','));
     }
 
@@ -158,8 +158,8 @@ export class AdminService {
   }) {
     let params = new HttpParams();
 
-    params = params.append('skip', skip);
-    params = params.append('take', take);
+    if (skip) params = params.append('skip', skip);
+    if (take) params = params.append('take', take);
 
     return this.http.get<AdminUsersResponse>('/api/v1/admin/user', { params });
   }
diff --git a/libs/ui/src/lib/services/data.service.ts b/libs/ui/src/lib/services/data.service.ts
index 37443cd20..d8c524f4e 100644
--- a/libs/ui/src/lib/services/data.service.ts
+++ b/libs/ui/src/lib/services/data.service.ts
@@ -89,7 +89,7 @@ export class DataService {
   public buildFiltersAsQueryParams({ filters }: { filters?: Filter[] }) {
     let params = new HttpParams();
 
-    if (filters?.length > 0) {
+    if (filters && filters.length > 0) {
       const {
         ACCOUNT: filtersByAccount,
         ASSET_CLASS: filtersByAssetClass,
diff --git a/libs/ui/src/lib/shared/abstract-mat-form-field.ts b/libs/ui/src/lib/shared/abstract-mat-form-field.ts
index 628f0a659..ce8c447a5 100644
--- a/libs/ui/src/lib/shared/abstract-mat-form-field.ts
+++ b/libs/ui/src/lib/shared/abstract-mat-form-field.ts
@@ -137,7 +137,7 @@ export abstract class AbstractMatFormField<T>
 
   public ngDoCheck() {
     if (this.ngControl) {
-      this.errorState = this.ngControl.invalid && this.ngControl.touched;
+      this.errorState = !!(this.ngControl.invalid && this.ngControl.touched);
       this.stateChanges.next();
     }
   }
diff --git a/libs/ui/src/lib/symbol-autocomplete/symbol-autocomplete.component.ts b/libs/ui/src/lib/symbol-autocomplete/symbol-autocomplete.component.ts
index c74e8a077..e17044c3f 100644
--- a/libs/ui/src/lib/symbol-autocomplete/symbol-autocomplete.component.ts
+++ b/libs/ui/src/lib/symbol-autocomplete/symbol-autocomplete.component.ts
@@ -185,7 +185,7 @@ export class GfSymbolAutocompleteComponent
   public ngDoCheck() {
     if (this.ngControl) {
       this.validateRequired();
-      this.errorState = this.ngControl.invalid && this.ngControl.touched;
+      this.errorState = !!(this.ngControl.invalid && this.ngControl.touched);
       this.stateChanges.next();
     }
   }
@@ -225,7 +225,7 @@ export class GfSymbolAutocompleteComponent
       ? !super.value?.dataSource || !super.value?.symbol
       : false;
     if (requiredCheck) {
-      this.ngControl.control.setErrors({ invalidData: true });
+      this.ngControl.control?.setErrors({ invalidData: true });
     }
   }
 }
diff --git a/libs/ui/src/lib/tags-selector/tags-selector.component.ts b/libs/ui/src/lib/tags-selector/tags-selector.component.ts
index 7f1a8805e..6ed742019 100644
--- a/libs/ui/src/lib/tags-selector/tags-selector.component.ts
+++ b/libs/ui/src/lib/tags-selector/tags-selector.component.ts
@@ -77,7 +77,7 @@ export class GfTagsSelectorComponent
     this.tagInputControl.valueChanges
       .pipe(takeUntil(this.unsubscribeSubject))
       .subscribe((value) => {
-        this.filteredOptions.next(this.filterTags(value));
+        this.filteredOptions.next(this.filterTags(value ?? ''));
       });
 
     addIcons({ addCircleOutline, closeOutline });
@@ -100,21 +100,23 @@ export class GfTagsSelectorComponent
 
     if (!tag && this.hasPermissionToCreateTag) {
       tag = {
-        id: undefined,
+        id: '',
         name: event.option.value as string,
         userId: null
       };
     }
 
-    this.tagsSelected.update((tags) => {
-      return [...(tags ?? []), tag];
-    });
+    if (tag) {
+      this.tagsSelected.update((tags) => {
+        return [...(tags ?? []), tag];
+      });
+    }
 
     const newTags = this.tagsSelected();
     this.onChange(newTags);
     this.onTouched();
     this.tagInput.nativeElement.value = '';
-    this.tagInputControl.setValue(undefined);
+    this.tagInputControl.setValue(null);
   }
 
   public onRemoveTag(tag: Tag) {
diff --git a/libs/ui/src/lib/toggle/toggle.component.ts b/libs/ui/src/lib/toggle/toggle.component.ts
index be460f7fa..fb238556d 100644
--- a/libs/ui/src/lib/toggle/toggle.component.ts
+++ b/libs/ui/src/lib/toggle/toggle.component.ts
@@ -26,13 +26,15 @@ export class GfToggleComponent implements OnChanges {
 
   @Output() valueChange = new EventEmitter<Pick<ToggleOption, 'value'>>();
 
-  public optionFormControl = new FormControl<string>(undefined);
+  public optionFormControl = new FormControl<string | null>(null);
 
   public ngOnChanges() {
     this.optionFormControl.setValue(this.defaultValue);
   }
 
   public onValueChange() {
-    this.valueChange.emit({ value: this.optionFormControl.value });
+    if (this.optionFormControl.value !== null) {
+      this.valueChange.emit({ value: this.optionFormControl.value });
+    }
   }
 }
diff --git a/libs/ui/src/lib/treemap-chart/treemap-chart.component.ts b/libs/ui/src/lib/treemap-chart/treemap-chart.component.ts
index ce85c300e..a80876f6a 100644
--- a/libs/ui/src/lib/treemap-chart/treemap-chart.component.ts
+++ b/libs/ui/src/lib/treemap-chart/treemap-chart.component.ts
@@ -25,7 +25,7 @@ import {
 } from '@angular/core';
 import { DataSource } from '@prisma/client';
 import { Big } from 'big.js';
-import type { TooltipOptions, ChartData } from 'chart.js';
+import type { ChartData, TooltipOptions } from 'chart.js';
 import { LinearScale } from 'chart.js';
 import { Chart, Tooltip } from 'chart.js';
 import { TreemapController, TreemapElement } from 'chartjs-chart-treemap';
diff --git a/libs/ui/tsconfig.json b/libs/ui/tsconfig.json
index 04f4630bc..51348a52a 100644
--- a/libs/ui/tsconfig.json
+++ b/libs/ui/tsconfig.json
@@ -19,6 +19,7 @@
     "target": "es2020",
     // TODO: Remove once solved in tsconfig.base.json
     "strict": false,
+    "strictNullChecks": true,
     "noImplicitReturns": true,
     "noFallthroughCasesInSwitch": true
   },