diff --git a/frontend/src/features/issues/components/StatusWorkflow.tsx b/frontend/src/features/issues/components/StatusWorkflow.tsx
index 4fc47ca..c9025c0 100644
--- a/frontend/src/features/issues/components/StatusWorkflow.tsx
+++ b/frontend/src/features/issues/components/StatusWorkflow.tsx
@@ -26,7 +26,6 @@ const STATUS_ICONS = {
   in_progress: PlayCircle,
   in_review: Clock,
   blocked: AlertCircle,
-  done: CheckCircle2,
   closed: XCircle,
 } as const;
 
diff --git a/frontend/src/features/issues/constants.ts b/frontend/src/features/issues/constants.ts
index d33ae5a..5379328 100644
--- a/frontend/src/features/issues/constants.ts
+++ b/frontend/src/features/issues/constants.ts
@@ -22,14 +22,17 @@ export const STATUS_CONFIG: Record<IssueStatus, StatusConfig> = {
   in_progress: { label: 'In Progress', color: 'text-yellow-500' },
   in_review: { label: 'In Review', color: 'text-purple-500' },
   blocked: { label: 'Blocked', color: 'text-red-500' },
-  done: { label: 'Done', color: 'text-green-500' },
-  closed: { label: 'Closed', color: 'text-muted-foreground' },
+  closed: { label: 'Closed', color: 'text-green-500' },
 };
 
 /**
  * Priority configuration with labels and colors
  */
 export const PRIORITY_CONFIG: Record<IssuePriority, PriorityConfig> = {
+  critical: {
+    label: 'Critical',
+    color: 'bg-purple-100 text-purple-800 dark:bg-purple-900 dark:text-purple-200',
+  },
   high: { label: 'High', color: 'bg-red-100 text-red-800 dark:bg-red-900 dark:text-red-200' },
   medium: {
     label: 'Medium',
@@ -46,10 +49,9 @@ export const STATUS_TRANSITIONS: StatusTransition[] = [
   { from: 'open', to: 'in_progress', label: 'Start Work' },
   { from: 'in_progress', to: 'in_review', label: 'Submit for Review' },
   { from: 'in_progress', to: 'blocked', label: 'Mark Blocked' },
-  { from: 'in_review', to: 'done', label: 'Mark Done' },
+  { from: 'in_review', to: 'closed', label: 'Complete' },
   { from: 'in_review', to: 'in_progress', label: 'Request Changes' },
   { from: 'blocked', to: 'in_progress', label: 'Unblock' },
-  { from: 'done', to: 'closed', label: 'Close Issue' },
   { from: 'closed', to: 'open', label: 'Reopen' },
 ];
 
@@ -76,14 +78,13 @@ export const STATUS_ORDER: IssueStatus[] = [
   'in_progress',
   'in_review',
   'blocked',
-  'done',
   'closed',
 ];
 
 /**
  * All possible priorities in order
  */
-export const PRIORITY_ORDER: IssuePriority[] = ['high', 'medium', 'low'];
+export const PRIORITY_ORDER: IssuePriority[] = ['critical', 'high', 'medium', 'low'];
 
 /**
  * Sync status configuration
diff --git a/frontend/src/features/issues/hooks/useIssues.ts b/frontend/src/features/issues/hooks/useIssues.ts
index 6e4ffa6..03a9631 100644
--- a/frontend/src/features/issues/hooks/useIssues.ts
+++ b/frontend/src/features/issues/hooks/useIssues.ts
@@ -94,7 +94,7 @@ function filterAndSortIssues(
         case 'number':
           return (a.number - b.number) * direction;
         case 'priority': {
-          const priorityOrder = { high: 3, medium: 2, low: 1 };
+          const priorityOrder = { critical: 4, high: 3, medium: 2, low: 1 };
           return (priorityOrder[a.priority] - priorityOrder[b.priority]) * direction;
         }
         case 'updated_at':
diff --git a/frontend/src/features/issues/mocks.ts b/frontend/src/features/issues/mocks.ts
index cd0db17..cc9a997 100644
--- a/frontend/src/features/issues/mocks.ts
+++ b/frontend/src/features/issues/mocks.ts
@@ -16,6 +16,7 @@ export const mockIssues: IssueSummary[] = [
   {
     id: 'ISS-001',
     number: 42,
+    type: 'story',
     title: 'Implement user authentication flow',
     description:
       'Create complete authentication flow with login, register, and password reset.',
@@ -31,6 +32,7 @@ export const mockIssues: IssueSummary[] = [
   {
     id: 'ISS-002',
     number: 43,
+    type: 'task',
     title: 'Design product catalog component',
     description: 'Create reusable product card and catalog grid components.',
     status: 'in_review',
@@ -45,6 +47,7 @@ export const mockIssues: IssueSummary[] = [
   {
     id: 'ISS-003',
     number: 44,
+    type: 'bug',
     title: 'Fix cart total calculation bug',
     description: 'Cart total shows incorrect amount when discount is applied.',
     status: 'blocked',
@@ -60,6 +63,7 @@ export const mockIssues: IssueSummary[] = [
   {
     id: 'ISS-004',
     number: 45,
+    type: 'story',
     title: 'Add product search functionality',
     description: 'Implement full-text search with filters for the product catalog.',
     status: 'open',
@@ -74,9 +78,10 @@ export const mockIssues: IssueSummary[] = [
   {
     id: 'ISS-005',
     number: 46,
+    type: 'task',
     title: 'Optimize database queries for product listing',
     description: 'Performance optimization for product queries with pagination.',
-    status: 'done',
+    status: 'closed',
     priority: 'low',
     labels: ['performance', 'backend', 'database'],
     sprint: 'Sprint 2',
@@ -88,9 +93,10 @@ export const mockIssues: IssueSummary[] = [
   {
     id: 'ISS-006',
     number: 47,
+    type: 'task',
     title: 'Create checkout page wireframes',
     description: 'Design wireframes for the checkout flow including payment selection.',
-    status: 'done',
+    status: 'closed',
     priority: 'high',
     labels: ['design', 'checkout', 'ui'],
     sprint: 'Sprint 2',
@@ -102,6 +108,7 @@ export const mockIssues: IssueSummary[] = [
   {
     id: 'ISS-007',
     number: 48,
+    type: 'story',
     title: 'Implement responsive navigation',
     description: 'Create mobile-friendly navigation with hamburger menu.',
     status: 'open',
@@ -116,6 +123,7 @@ export const mockIssues: IssueSummary[] = [
   {
     id: 'ISS-008',
     number: 49,
+    type: 'task',
     title: 'Set up E2E test framework',
     description: 'Configure Playwright for end-to-end testing.',
     status: 'in_progress',
@@ -135,6 +143,7 @@ export const mockIssues: IssueSummary[] = [
 export const mockIssueDetail: IssueDetail = {
   id: 'ISS-001',
   number: 42,
+  type: 'story',
   title: 'Implement user authentication flow',
   description: `## Overview
 Create a complete authentication flow for the e-commerce platform.
diff --git a/frontend/src/features/issues/types/index.ts b/frontend/src/features/issues/types/index.ts
index 351e699..682cfad 100644
--- a/frontend/src/features/issues/types/index.ts
+++ b/frontend/src/features/issues/types/index.ts
@@ -8,14 +8,22 @@
  */
 
 /**
- * Issue status values
+ * Issue type values (for hierarchy: Epic -> Story -> Task)
+ * Matches backend: IssueType enum in app/models/syndarix/enums.py
  */
-export type IssueStatus = 'open' | 'in_progress' | 'in_review' | 'blocked' | 'done' | 'closed';
+export type IssueType = 'epic' | 'story' | 'task' | 'bug';
+
+/**
+ * Issue status values
+ * Matches backend: IssueStatus enum in app/models/syndarix/enums.py
+ */
+export type IssueStatus = 'open' | 'in_progress' | 'in_review' | 'blocked' | 'closed';
 
 /**
  * Issue priority values
+ * Matches backend: IssuePriority enum in app/models/syndarix/enums.py
  */
-export type IssuePriority = 'high' | 'medium' | 'low';
+export type IssuePriority = 'low' | 'medium' | 'high' | 'critical';
 
 /**
  * Sync status with external trackers
@@ -64,6 +72,7 @@ export interface IssueActivity {
 export interface IssueSummary {
   id: string;
   number: number;
+  type: IssueType;
   title: string;
   description: string;
   status: IssueStatus;