diff --git a/app/(landing)/organizations/[id]/hackathons/page.tsx b/app/(landing)/organizations/[id]/hackathons/page.tsx
index 9a9935184..bae47be3d 100644
--- a/app/(landing)/organizations/[id]/hackathons/page.tsx
+++ b/app/(landing)/organizations/[id]/hackathons/page.tsx
@@ -32,7 +32,7 @@ const calculateDraftCompletion = (draft: HackathonDraft): number => {
     draft.information?.title,
     draft.information?.banner,
     draft.information?.description,
-    draft.information?.category,
+    draft.information?.categories,
     draft.timeline?.startDate,
     draft.timeline?.submissionDeadline,
     draft.timeline?.judgingDate,
@@ -123,8 +123,9 @@ export default function HackathonsPage() {
 
     if (categoryFilter !== 'all') {
       filtered = filtered.filter(item => {
-        const category = item.data.information?.category?.toLowerCase() || '';
-        return category === categoryFilter.toLowerCase();
+        const category =
+          item.data.information?.categories?.join(',')?.toLowerCase() || '';
+        return category.includes(categoryFilter.toLowerCase());
       });
     }
 
diff --git a/components/organization/hackathons/new/NewHackathonTab.tsx b/components/organization/hackathons/new/NewHackathonTab.tsx
index c4ceba7ce..175a13972 100644
--- a/components/organization/hackathons/new/NewHackathonTab.tsx
+++ b/components/organization/hackathons/new/NewHackathonTab.tsx
@@ -113,6 +113,7 @@ export default function NewHackathonTab({
   const { isPublishing, publish } = useHackathonPublish({
     organizationId: derivedOrgId || '',
     stepData,
+    draftId,
     publishHackathonAction,
   });
 
diff --git a/components/organization/hackathons/new/tabs/InfoTab.tsx b/components/organization/hackathons/new/tabs/InfoTab.tsx
index 6292bde18..6c48054f5 100644
--- a/components/organization/hackathons/new/tabs/InfoTab.tsx
+++ b/components/organization/hackathons/new/tabs/InfoTab.tsx
@@ -52,11 +52,9 @@ export default function InfoTab({
       name: initialData?.name || '',
       banner: initialData?.banner || '',
       description: initialData?.description || '',
-      category: Array.isArray(initialData?.category)
-        ? initialData.category
-        : initialData?.category
-          ? [initialData.category]
-          : [],
+      categories: Array.isArray(initialData?.categories)
+        ? initialData.categories
+        : [],
       venueType: initialData?.venueType || 'physical',
       country: initialData?.country || '',
       state: initialData?.state || '',
@@ -145,7 +143,7 @@ export default function InfoTab({
           )}
         />
 
-        <CategorySelection control={form.control} name='category' />
+        <CategorySelection control={form.control} name='categories' />
 
         <VenueSection
           control={form.control}
diff --git a/components/organization/hackathons/new/tabs/components/review/InformationSection.tsx b/components/organization/hackathons/new/tabs/components/review/InformationSection.tsx
index f45b250f6..8ad3b617e 100644
--- a/components/organization/hackathons/new/tabs/components/review/InformationSection.tsx
+++ b/components/organization/hackathons/new/tabs/components/review/InformationSection.tsx
@@ -83,9 +83,7 @@ export default function InformationSection({
         <InfoItem
           label='Categories'
           value={
-            Array.isArray(data.category)
-              ? data.category.join(', ')
-              : data.category || ''
+            Array.isArray(data.categories) ? data.categories.join(', ') : ''
           }
         />
         <Separator className='bg-gray-900' />
diff --git a/components/organization/hackathons/new/tabs/schemas/infoSchema.ts b/components/organization/hackathons/new/tabs/schemas/infoSchema.ts
index 0fba03a13..87d055722 100644
--- a/components/organization/hackathons/new/tabs/schemas/infoSchema.ts
+++ b/components/organization/hackathons/new/tabs/schemas/infoSchema.ts
@@ -19,7 +19,7 @@ export const infoSchema = z
       .min(10, 'Description must be at least 10 characters')
       .max(5000, 'Description must be less than 5000 characters'),
 
-    category: z
+    categories: z
       .array(
         z.enum([
           'DeFi',
diff --git a/components/organization/hackathons/settings/GeneralSettingsTab.tsx b/components/organization/hackathons/settings/GeneralSettingsTab.tsx
index f98481b00..835958ceb 100644
--- a/components/organization/hackathons/settings/GeneralSettingsTab.tsx
+++ b/components/organization/hackathons/settings/GeneralSettingsTab.tsx
@@ -78,11 +78,9 @@ export default function GeneralSettingsTab({
       name: initialData?.name || '',
       banner: initialData?.banner || '',
       description: initialData?.description || '',
-      category: Array.isArray(initialData?.category)
-        ? initialData.category
-        : initialData?.category
-          ? [initialData.category]
-          : [],
+      categories: Array.isArray(initialData?.categories)
+        ? initialData.categories
+        : [],
       venueType: initialData?.venueType || 'virtual',
       country: initialData?.country || '',
       state: initialData?.state || '',
@@ -205,7 +203,7 @@ export default function GeneralSettingsTab({
             )}
           />
 
-          <CategorySelection control={form.control} name='category' />
+          <CategorySelection control={form.control} name='categories' />
 
           <VenueSection
             control={form.control}
diff --git a/hooks/hackathon/use-hackathon-transform.ts b/hooks/hackathon/use-hackathon-transform.ts
index 9365a181d..2ddbe4382 100644
--- a/hooks/hackathon/use-hackathon-transform.ts
+++ b/hooks/hackathon/use-hackathon-transform.ts
@@ -125,14 +125,12 @@ export function useHackathonTransform() {
         extendedHackathon._organizationName ||
         'organization';
 
-      // Extract categories - support both single category and multiple categories
+      // Extract categories
       const categories: string[] = [];
-      if (hackathon.information?.category) {
-        // If category is an array, use it; otherwise convert single category to array
-        if (Array.isArray(hackathon.information.category)) {
-          categories.push(...hackathon.information.category);
-        } else {
-          categories.push(hackathon.information.category);
+      if (hackathon.information?.categories) {
+        // If categories is an array, use it
+        if (Array.isArray(hackathon.information.categories)) {
+          categories.push(...hackathon.information.categories);
         }
       }
       // Add additional categories if they exist in the hackathon object
diff --git a/hooks/use-hackathon-publish.ts b/hooks/use-hackathon-publish.ts
index 5a5ef3ca9..a70215618 100644
--- a/hooks/use-hackathon-publish.ts
+++ b/hooks/use-hackathon-publish.ts
@@ -40,6 +40,7 @@ interface StepData {
 interface UseHackathonPublishProps {
   organizationId: string;
   stepData: StepData;
+  draftId?: string | null;
   publishHackathonAction: (
     data: PublishHackathonRequest
   ) => Promise<{ _id: string }>;
@@ -48,6 +49,7 @@ interface UseHackathonPublishProps {
 export const useHackathonPublish = ({
   organizationId,
   stepData,
+  draftId,
   publishHackathonAction,
 }: UseHackathonPublishProps) => {
   const router = useRouter();
@@ -196,6 +198,9 @@ export const useHackathonPublish = ({
 
       toast.info('Publishing hackathon...');
       const apiData = transformToApiFormat(stepData) as PublishHackathonRequest;
+      if (draftId) {
+        apiData.draftId = draftId;
+      }
       apiData.contractId = contractId;
       apiData.escrowAddress = escrowAddress;
       apiData.transactionHash = transactionHash;
diff --git a/lib/api/hackathons.ts b/lib/api/hackathons.ts
index 778880906..614694f57 100644
--- a/lib/api/hackathons.ts
+++ b/lib/api/hackathons.ts
@@ -42,10 +42,9 @@ export interface HackathonInformation {
   title: string;
   banner: string;
   description: string;
-  category?: HackathonCategory; // Legacy format (single category)
-  categories?: HackathonCategory[]; // New format (array of categories)
-  venue?: HackathonVenue;
+  categories: HackathonCategory[]; // New format (array of categories)
   slug: string;
+  venue?: HackathonVenue;
 }
 
 // Timeline Tab Types
@@ -177,6 +176,7 @@ export type CreateDraftRequest = Partial<HackathonData>;
 export type UpdateDraftRequest = Partial<HackathonData>;
 
 export interface PublishHackathonRequest extends HackathonData {
+  draftId?: string;
   contractId?: string;
   escrowAddress?: string;
   transactionHash?: string;
@@ -709,7 +709,6 @@ interface FlatHackathonData {
   // Flat fields that map to nested structure
   banner?: string;
   description?: string;
-  category?: string | HackathonCategory; // Legacy format
   categories?: HackathonCategory[]; // New format
   venue?: HackathonVenue;
   startDate?: string;
@@ -786,10 +785,7 @@ const transformHackathonResponse = (
       // Support both new format (categories) and legacy format (category)
       categories: Array.isArray(flat.categories)
         ? (flat.categories as HackathonCategory[])
-        : flat.category
-          ? [flat.category as HackathonCategory]
-          : [HackathonCategory.OTHER],
-      category: (flat.category as HackathonCategory) || HackathonCategory.OTHER,
+        : [HackathonCategory.OTHER],
       venue: flat.venue,
     },
     timeline: {
@@ -1382,13 +1378,22 @@ export const transformPublicHackathonToHackathon = (
     internalStatus = 'completed';
   }
 
-  // Get first category or default to OTHER
-  const category = publicHackathon.categories?.[0] || HackathonCategory.OTHER;
-  const categoryEnum = Object.values(HackathonCategory).includes(
-    category as HackathonCategory
-  )
-    ? (category as HackathonCategory)
-    : HackathonCategory.OTHER;
+  // Map all categories from API response
+  const categoriesArray: HackathonCategory[] = publicHackathon.categories
+    ? publicHackathon.categories
+        .map(cat => {
+          // Check if the category string matches any HackathonCategory enum value
+          const matchedCategory = Object.values(HackathonCategory).find(
+            enumCat => enumCat === cat
+          );
+          return matchedCategory || null;
+        })
+        .filter((cat): cat is HackathonCategory => cat !== null)
+    : [];
+
+  // Ensure at least one category
+  const categories: HackathonCategory[] =
+    categoriesArray.length > 0 ? categoriesArray : [HackathonCategory.OTHER];
 
   // Extract resources (telegram, discord, etc.) from resources array
   const telegram = publicHackathon.resources?.find(
@@ -1412,7 +1417,7 @@ export const transformPublicHackathonToHackathon = (
       title: publicHackathon.title,
       banner: publicHackathon.imageUrl,
       description: publicHackathon.description,
-      category: categoryEnum,
+      categories: categories,
       slug: publicHackathon.slug,
       venue,
     },
diff --git a/lib/utils/hackathon-form-transforms.ts b/lib/utils/hackathon-form-transforms.ts
index 6b7089eb6..e7a429e13 100644
--- a/lib/utils/hackathon-form-transforms.ts
+++ b/lib/utils/hackathon-form-transforms.ts
@@ -28,14 +28,12 @@ export const transformToApiFormat = (stepData: {
   const judging = stepData.judging;
   const collaboration = stepData.collaboration;
 
-  // Convert form category array to API format
-  const categoriesArray: HackathonCategory[] = Array.isArray(info?.category)
-    ? (info.category as HackathonCategory[]).filter(cat =>
+  // Convert form categories array to API format
+  const categoriesArray: HackathonCategory[] = Array.isArray(info?.categories)
+    ? (info.categories as HackathonCategory[]).filter(cat =>
         Object.values(HackathonCategory).includes(cat)
       )
-    : info?.category && typeof info.category === 'string'
-      ? [info.category as HackathonCategory]
-      : [];
+    : [];
 
   return {
     information: {
@@ -48,11 +46,6 @@ export const transformToApiFormat = (stepData: {
         categoriesArray.length > 0
           ? categoriesArray
           : [HackathonCategory.OTHER],
-      // Also include legacy category for backward compatibility (first category)
-      category:
-        categoriesArray.length > 0
-          ? categoriesArray[0]
-          : HackathonCategory.OTHER,
       venue: {
         type: (info?.venueType as VenueType) || VenueType.VIRTUAL,
         country: info?.country,
@@ -144,19 +137,15 @@ export const transformFromApiFormat = (draft: HackathonDraft) => {
   const judging = draft.judging;
   const collaboration = draft.collaboration;
 
-  // Handle both new format (categories array) and legacy format (category string)
-  const categoriesArray: string[] = info?.categories
-    ? info.categories
-    : info?.category
-      ? [info.category]
-      : [];
+  // Handle categories array
+  const categoriesArray: string[] = info?.categories ? info.categories : [];
 
   return {
     information: {
       name: info?.title || '',
       banner: info?.banner || '',
       description: info?.description || '',
-      category: categoriesArray,
+      categories: categoriesArray,
       venueType: info?.venue?.type || 'physical',
       country: info?.venue?.country || '',
       state: info?.venue?.state || '',