diff --git a/frontend/src/modules/contributor/components/details/contributor-details-activities.vue b/frontend/src/modules/contributor/components/details/contributor-details-activities.vue
index 0af20b6c48..efb60feecb 100644
--- a/frontend/src/modules/contributor/components/details/contributor-details-activities.vue
+++ b/frontend/src/modules/contributor/components/details/contributor-details-activities.vue
@@ -26,7 +26,7 @@
     :entity="props.contributor"
     entity-type="member"
     show-affiliations
-    :selected-segment="subProjectId || null"
+    :selected-segment="subProjectId || undefined"
     class="max-w-full"
   />
 </template>
@@ -47,10 +47,11 @@ const route = useRoute();
 
 const timeline = ref<InstanceType<typeof AppActivityTimeline> | null>(null);
 
-const { subProjectId } = route.query;
+// shortcut: ignores array query values, as on main. revisit: when route queries are typed.
+const subProjectId = route.query.subProjectId as string | undefined;
 
 const loadMore = () => {
-  timeline.value.fetchActivities();
+  timeline.value?.fetchActivities();
 };
 
 // eslint-disable-next-line vue/define-macros-order -- plain <script> below counts as last, https://eslint.vuejs.org/rules/define-macros-order.html
diff --git a/frontend/src/modules/contributor/components/details/contributor-details-header.vue b/frontend/src/modules/contributor/components/details/contributor-details-header.vue
index 9a0de29226..9198863c9a 100644
--- a/frontend/src/modules/contributor/components/details/contributor-details-header.vue
+++ b/frontend/src/modules/contributor/components/details/contributor-details-header.vue
@@ -40,6 +40,7 @@ import { computed } from 'vue';
 import { contributorDetailsHeaderProfilePlatforms } from '@/modules/contributor/config/details-header-profile-platforms';
 import LfContributorEditName from '@/modules/contributor/components/edit/contributor-edit-name.vue';
 import type { Contributor } from '@/modules/contributor/types/Contributor';
+import type { Platform } from '@/shared/modules/platform/types/Platform';
 import useContributorHelpers from '@/modules/contributor/helpers/contributor.helpers';
 import LfContributorWorkPosition from '@/modules/contributor/components/shared/contributor-work-position.vue';
 import LfContributorDetailsHeaderProfiles
@@ -56,7 +57,7 @@ const {
 } = useContributorHelpers();
 
 const hasHeaderIdentities = computed(
-  () => (props.contributor.identities || []).some((i) => contributorDetailsHeaderProfilePlatforms.includes(i.platform)),
+  () => (props.contributor.identities || []).some((i) => contributorDetailsHeaderProfilePlatforms.includes(i.platform as Platform)),
 );
 
 const organization = computed(() => activeProfileOrganization(props.contributor));
diff --git a/frontend/src/modules/contributor/components/details/contributor-details-identities.vue b/frontend/src/modules/contributor/components/details/contributor-details-identities.vue
index bad2a280d6..132784d6c6 100644
--- a/frontend/src/modules/contributor/components/details/contributor-details-identities.vue
+++ b/frontend/src/modules/contributor/components/details/contributor-details-identities.vue
@@ -143,7 +143,7 @@ const selectedIdentity = ref<string | null>(null);
 
 const addIdentity = ref<boolean>(false);
 const addIdentityTemplate = ref<Partial<ContributorIdentity> | null>(null);
-const editIdentity = ref<Partial<ContributorIdentity> | null>(null);
+const editIdentity = ref<ContributorIdentity | null>(null);
 
 const unmerge = (identityId: string) => {
   if (identityId) {
diff --git a/frontend/src/modules/contributor/components/details/header/contributor-details-header-profiles.vue b/frontend/src/modules/contributor/components/details/header/contributor-details-header-profiles.vue
index 84e7a0add1..f536b31eab 100644
--- a/frontend/src/modules/contributor/components/details/header/contributor-details-header-profiles.vue
+++ b/frontend/src/modules/contributor/components/details/header/contributor-details-header-profiles.vue
@@ -48,7 +48,7 @@ opacity-0 invisible transition group-hover:visible group-hover:opacity-100 z-30
         <a
           v-for="identity of idents"
           :key="`${platform}-${identity.value}`"
-          :href="identity.url"
+          :href="identity.url ?? undefined"
           class="flex items-center justify-between p-2 transition"
           :class="identity.url ? 'hover:bg-gray-50' : ''"
           target="_blank"
@@ -80,6 +80,7 @@ import useContributorHelpers from '@/modules/contributor/helpers/contributor.hel
 import { contributorDetailsHeaderProfilePlatforms } from '@/modules/contributor/config/details-header-profile-platforms';
 import type { Contributor } from '@/modules/contributor/types/Contributor';
 import { lfIdentities } from '@/config/identities';
+import type { Platform } from '@/shared/modules/platform/types/Platform';
 
 const props = defineProps<{
   contributor: Contributor,
@@ -88,10 +89,10 @@ const props = defineProps<{
 const { identities } = useContributorHelpers();
 
 const platformIdentities = computed(() => {
-  const data = {};
+  const data: Record<string, ReturnType<typeof identities>> = {};
   contributorDetailsHeaderProfilePlatforms.forEach((p) => { data[p] = []; });
   identities(props.contributor).forEach((i) => {
-    if (contributorDetailsHeaderProfilePlatforms.includes(i.platform)) {
+    if (contributorDetailsHeaderProfilePlatforms.includes(i.platform as Platform)) {
       data[i.platform].push(i);
     }
   });
diff --git a/frontend/src/modules/contributor/components/details/overview/contributor-details-projects.vue b/frontend/src/modules/contributor/components/details/overview/contributor-details-projects.vue
index 97472e20df..b3b07b84ef 100644
--- a/frontend/src/modules/contributor/components/details/overview/contributor-details-projects.vue
+++ b/frontend/src/modules/contributor/components/details/overview/contributor-details-projects.vue
@@ -167,15 +167,17 @@ const isAffilationEditOpen = ref<boolean>(false);
 const getAffiliations = (projectId: string) => (props.contributor.affiliations || [])
   .filter((affiliation) => affiliation.segmentId === projectId)
   .reduce((obj: Record<string, ContributorAffiliation[]>, aff: ContributorAffiliation) => {
-    if (!obj[aff.organizationId]) {
+    // shortcut: a null organizationId keys as "null", as on main. revisit: when affiliations carry no null orgs.
+    const orgId = aff.organizationId as string;
+    if (!obj[orgId]) {
       return {
         ...obj,
-        [aff.organizationId]: [aff],
+        [orgId]: [aff],
       };
     }
     return {
       ...obj,
-      [aff.organizationId]: [...obj[aff.organizationId], aff],
+      [orgId]: [...obj[orgId], aff],
     };
   }, {});
 
diff --git a/frontend/src/modules/contributor/components/details/overview/project/contributor-details-projects-affiliation.vue b/frontend/src/modules/contributor/components/details/overview/project/contributor-details-projects-affiliation.vue
index cb35e77aca..ef1c6205b6 100644
--- a/frontend/src/modules/contributor/components/details/overview/project/contributor-details-projects-affiliation.vue
+++ b/frontend/src/modules/contributor/components/details/overview/project/contributor-details-projects-affiliation.vue
@@ -113,7 +113,7 @@ import LfBadge from '@/ui-kit/badge/Badge.vue';
 import { dateHelper } from '@/shared/date-helper/date-helper';
 
 const props = defineProps<{
-  project: any,
+  project: { affiliations: Record<string, ContributorAffiliation[]> },
 }>();
 
 const { selectedProjectGroup } = storeToRefs(useLfSegmentsStore());
diff --git a/frontend/src/modules/contributor/components/details/overview/project/contributor-details-projects-sorting.vue b/frontend/src/modules/contributor/components/details/overview/project/contributor-details-projects-sorting.vue
index d53d8b83bd..ed2c9efe0d 100644
--- a/frontend/src/modules/contributor/components/details/overview/project/contributor-details-projects-sorting.vue
+++ b/frontend/src/modules/contributor/components/details/overview/project/contributor-details-projects-sorting.vue
@@ -28,7 +28,7 @@ const props = defineProps<{
   sorting: string,
 }>();
 
-const emit = defineEmits<{(e: 'update:sorting', value: string)}>();
+const emit = defineEmits<{(e: 'update:sorting', value: string): void}>();
 
 const sortBy = computed({
   get: () => props.sorting,
diff --git a/frontend/src/modules/contributor/components/edit/contributor-add.vue b/frontend/src/modules/contributor/components/edit/contributor-add.vue
index 86e2d8f14f..ff011d8942 100644
--- a/frontend/src/modules/contributor/components/edit/contributor-add.vue
+++ b/frontend/src/modules/contributor/components/edit/contributor-add.vue
@@ -125,7 +125,7 @@ import LfButton from '@/ui-kit/button/Button.vue';
 import LfIcon from '@/ui-kit/icon/Icon.vue';
 import LfInput from '@/ui-kit/input/Input.vue';
 import LfField from '@/ui-kit/field/Field.vue';
-import type { Contributor, ContributorIdentity } from '@/modules/contributor/types/Contributor';
+import type { CreateContributorIdentity, CreateContributorPayload } from '@/modules/contributor/types/Contributor';
 import LfTooltip from '@/ui-kit/tooltip/Tooltip.vue';
 import useVuelidate from '@vuelidate/core';
 import { required } from '@vuelidate/validators';
@@ -161,11 +161,7 @@ const { memberIdentities } = useIdentitiesHelpers();
 
 const { selectedProjectGroup } = storeToRefs(useLfSegmentsStore());
 
-type ContributorAddIdentity = ContributorIdentity & {
-  // image: string,
-  // prefix: string,
-  // placeholder: string,
-}
+type ContributorAddIdentity = CreateContributorIdentity;
 
 const platformList: ContributorAddIdentity[] = memberIdentities
   .map((config: IdentityConfig) => ({
@@ -199,7 +195,7 @@ const rules = {
     required,
   },
   email: {
-    required: (value: ContributorAddIdentity[]) => value.some((i) => i.length),
+    required: (value: string[]) => value.some((i) => i.length),
   },
   identities: {
     required: (value: ContributorAddIdentity[]) => value.some((i) => i.value.length),
@@ -222,7 +218,7 @@ const createContributor = () => {
     return;
   }
 
-  const data: Partial<Contributor> = {
+  const data: CreateContributorPayload = {
     displayName: form.name,
     identities: [
       ...form.identities
diff --git a/frontend/src/modules/contributor/components/edit/work-history/contributor-work-history-edit.vue b/frontend/src/modules/contributor/components/edit/work-history/contributor-work-history-edit.vue
index 29fa99c665..085e7303cb 100644
--- a/frontend/src/modules/contributor/components/edit/work-history/contributor-work-history-edit.vue
+++ b/frontend/src/modules/contributor/components/edit/work-history/contributor-work-history-edit.vue
@@ -147,7 +147,7 @@ const isEdit = computed(() => !!props.organization);
 const sending = ref<boolean>(false);
 
 interface ConrtibutorWorkHistoryForm {
-  organization: Organization | null,
+  organization: (Organization & { label?: string }) | null,
   title: string;
   dateStart: string | null;
   dateEnd: string | null;
@@ -210,21 +210,6 @@ const updateWorkExperience = () => {
     });
   }
 
-  let orgs: Organization[] = [...(props.contributor.organizations || [])];
-  if (isEdit.value) {
-    orgs = orgs.map((o: Organization) => {
-      if (o.id === props.organization?.id
-          && o.memberOrganizations?.title === props.organization?.memberOrganizations?.title
-          && o.memberOrganizations?.dateStart === props.organization?.memberOrganizations?.dateStart
-          && o.memberOrganizations?.dateEnd === props.organization?.memberOrganizations?.dateEnd) {
-        return data;
-      }
-      return o;
-    });
-  } else {
-    orgs.push(data);
-  }
-
   sending.value = true;
 
   (isEdit.value
diff --git a/frontend/src/modules/contributor/helpers/contributor.helpers.ts b/frontend/src/modules/contributor/helpers/contributor.helpers.ts
index 55c09c6269..8985785060 100644
--- a/frontend/src/modules/contributor/helpers/contributor.helpers.ts
+++ b/frontend/src/modules/contributor/helpers/contributor.helpers.ts
@@ -82,29 +82,37 @@ const useContributorHelpers = () => {
   // Mirrors sortActiveOrganizations in services/libs/data-access-layer/src/members/dataProcessor.ts
   const activeProfileOrganization = (contributor: Contributor) => {
     const time = (date?: string) => (date ? new Date(date).getTime() : 0);
-    const range = (mo: MemberOrganization) => (mo.dateEnd ? time(mo.dateEnd) : Date.parse('9999-12-31')) - time(mo.dateStart);
+    const range = (mo: MemberOrganization) =>
+      (mo.dateEnd ? time(mo.dateEnd) : Date.parse('9999-12-31')) - time(mo.dateStart);
 
-    return (contributor.organizations || [])
-      .filter((org) => !org.memberOrganizations.dateEnd)
-      .sort((a, b) => {
-        const aMo = a.memberOrganizations;
-        const bMo = b.memberOrganizations;
-        const rank = Number(bMo.affiliationOverride?.allowAffiliation !== false)
-          - Number(aMo.affiliationOverride?.allowAffiliation !== false)
-          || Number(bMo.affiliationOverride?.isPrimaryWorkExperience === true)
-          - Number(aMo.affiliationOverride?.isPrimaryWorkExperience === true)
-          || Number(!!bMo.dateStart) - Number(!!aMo.dateStart);
+    return (
+      (contributor.organizations || [])
+        .filter((org) => !org.memberOrganizations.dateEnd)
+        .sort((a, b) => {
+          const aMo = a.memberOrganizations;
+          const bMo = b.memberOrganizations;
+          const rank =
+            Number(bMo.affiliationOverride?.allowAffiliation !== false) -
+              Number(aMo.affiliationOverride?.allowAffiliation !== false) ||
+            Number(bMo.affiliationOverride?.isPrimaryWorkExperience === true) -
+              Number(aMo.affiliationOverride?.isPrimaryWorkExperience === true) ||
+            Number(!!bMo.dateStart) - Number(!!aMo.dateStart);
 
-        if (rank) {
-          return rank;
-        }
-        if (aMo.dateStart) {
-          return range(bMo) - range(aMo) || aMo.id.localeCompare(bMo.id);
-        }
-        return time(b.createdAt) - time(a.createdAt)
-          || (a.displayName || '').localeCompare(b.displayName || '', undefined, { sensitivity: 'base' })
-          || aMo.id.localeCompare(bMo.id);
-      })[0] || null;
+          if (rank) {
+            return rank;
+          }
+          if (aMo.dateStart) {
+            return range(bMo) - range(aMo) || aMo.id.localeCompare(bMo.id);
+          }
+          return (
+            time(b.createdAt) - time(a.createdAt) ||
+            (a.displayName || '').localeCompare(b.displayName || '', undefined, {
+              sensitivity: 'base',
+            }) ||
+            aMo.id.localeCompare(bMo.id)
+          );
+        })[0] || null
+    );
   };
 
   return {
diff --git a/frontend/src/modules/contributor/pages/contributor-details.page.vue b/frontend/src/modules/contributor/pages/contributor-details.page.vue
index 13928c26c5..d767b8d1d7 100644
--- a/frontend/src/modules/contributor/pages/contributor-details.page.vue
+++ b/frontend/src/modules/contributor/pages/contributor-details.page.vue
@@ -161,12 +161,11 @@ const fetchContributor = () => {
   });
 };
 
-const controlScroll = (e: {
-  target: { scrollTop: any; clientHeight: any; scrollHeight: number };
-}) => {
+const controlScroll = (e: Event) => {
+  const target = e.target as HTMLElement;
   if (
-    e.target.scrollTop + e.target.clientHeight
-    >= e.target.scrollHeight - 10
+    target.scrollTop + target.clientHeight
+    >= target.scrollHeight - 10
   ) {
     if (tabs.value === 'activities') {
       activities.value.loadMore();
diff --git a/frontend/src/modules/contributor/services/contributor.api.service.ts b/frontend/src/modules/contributor/services/contributor.api.service.ts
index 4b737ed879..2b9074af08 100644
--- a/frontend/src/modules/contributor/services/contributor.api.service.ts
+++ b/frontend/src/modules/contributor/services/contributor.api.service.ts
@@ -1,6 +1,6 @@
 import { storeToRefs } from 'pinia';
 import authAxios from '@/shared/axios/auth-axios';
-import type { Contributor } from '@/modules/contributor/types/Contributor';
+import type { Contributor, CreateContributorPayload } from '@/modules/contributor/types/Contributor';
 import { useLfSegmentsStore } from '@/modules/lf/segments/store';
 
 const getSegments = () => {
@@ -54,7 +54,7 @@ export class ContributorApiService {
     ).then(({ data }) => Promise.resolve(data));
   }
 
-  static async create(data: Partial<Contributor>, segments: string[]) {
+  static async create(data: CreateContributorPayload, segments: string[]) {
     const response = await authAxios.post(
       '/member',
       {
diff --git a/frontend/src/modules/contributor/types/Contributor.ts b/frontend/src/modules/contributor/types/Contributor.ts
index 3cdf425674..a90a29b4d8 100644
--- a/frontend/src/modules/contributor/types/Contributor.ts
+++ b/frontend/src/modules/contributor/types/Contributor.ts
@@ -12,7 +12,7 @@ export interface ContributorAttribute {
 }
 
 export interface ContributorMaintainerRole {
-  id: string
+  id: string;
   dateEnd: string | null;
   dateStart: string;
   memberId: string;
@@ -92,13 +92,13 @@ export interface Contributor {
   activeDaysCount: string;
   activeOn: string[] | null;
   activityCount: string;
-  activityTypes:string[] | null;
-  attributes: Record<string, ContributorAttribute>
+  activityTypes: string[] | null;
+  attributes: Record<string, ContributorAttribute>;
   averageSentiment: number | null;
-  contributions: ContributorContribution[]
+  contributions: ContributorContribution[];
   createdAt: string;
   displayName: string;
-  emails: string[]
+  emails: string[];
   id: string;
   identities: ContributorIdentity[];
   importHash: string | null;
@@ -108,11 +108,11 @@ export interface Contributor {
   noMergeIds: string[] | null;
   numberOfOpenSourceContributions: number | null;
   organizations: Organization[];
-  reach:ContributorReach;
+  reach: ContributorReach;
   score: number;
   toMergeIds: string[] | null;
   updatedAt: string;
-  username: Record<string, string[]>
+  username: Record<string, string[]>;
   verifiedEmails: string[];
   unverifiedEmails: string[];
   affiliations: ContributorAffiliation[];
@@ -121,7 +121,12 @@ export interface Contributor {
     id: string;
     name: string;
     activityCount: string;
-  }[],
+  }[];
   maintainerRoles: ContributorMaintainerRole[];
   activitySycning: MergeAction | null;
 }
+
+export type CreateContributorPayload = Omit<Partial<Contributor>, 'identities'> & {
+  identities?: CreateContributorIdentity[];
+  manuallyCreated?: boolean;
+};
diff --git a/frontend/typecheck-baseline.json b/frontend/typecheck-baseline.json
index 6055859b8d..394e1c5636 100644
--- a/frontend/typecheck-baseline.json
+++ b/frontend/typecheck-baseline.json
@@ -1 +1 @@
-{ "errors": 160 }
+{ "errors": 121 }