diff --git a/frontend/src/components/__tests__/Field.test.jsx b/frontend/src/components/__tests__/Field.test.jsx
index 3f57356d..092871f1 100644
--- a/frontend/src/components/__tests__/Field.test.jsx
+++ b/frontend/src/components/__tests__/Field.test.jsx
@@ -5,20 +5,21 @@ import { Field } from '../Field';
 // Mock Mantine components
 vi.mock('@mantine/core', async () => {
   return {
-    TextInput: ({ label, description, value, onChange }) => (
+    TextInput: ({ label, description, value, onChange, type, placeholder }) => (
       <div>
         <label htmlFor="text-input">{label}</label>
         <input
           id="text-input"
-          type="text"
+          type={type || 'text'}
           value={value}
           onChange={onChange}
+          placeholder={placeholder}
           aria-describedby={description}
         />
         {description && <div>{description}</div>}
       </div>
     ),
-    NumberInput: ({ label, description, value, onChange }) => (
+    NumberInput: ({ label, description, value, onChange, placeholder }) => (
       <div>
         <label htmlFor="number-input">{label}</label>
         <input
@@ -26,6 +27,20 @@ vi.mock('@mantine/core', async () => {
           type="number"
           value={value}
           onChange={(e) => onChange(Number(e.target.value))}
+          placeholder={placeholder}
+          aria-describedby={description}
+        />
+        {description && <div>{description}</div>}
+      </div>
+    ),
+    Textarea: ({ label, description, value, onChange, placeholder }) => (
+      <div>
+        <label htmlFor="textarea-input">{label}</label>
+        <textarea
+          id="textarea-input"
+          value={value}
+          onChange={onChange}
+          placeholder={placeholder}
           aria-describedby={description}
         />
         {description && <div>{description}</div>}
@@ -44,13 +59,14 @@ vi.mock('@mantine/core', async () => {
         {description && <div>{description}</div>}
       </div>
     ),
-    Select: ({ label, description, value, data, onChange }) => (
+    Select: ({ label, description, value, data, onChange, placeholder }) => (
       <div>
         <label htmlFor="select-input">{label}</label>
         <select
           id="select-input"
           value={value}
           onChange={(e) => onChange(e.target.value)}
+          placeholder={placeholder}
           aria-describedby={description}
         >
           {data.map((option) => (
@@ -62,6 +78,11 @@ vi.mock('@mantine/core', async () => {
         {description && <div>{description}</div>}
       </div>
     ),
+    Text: ({ children, fw, size, c }) => (
+      <div data-fw={fw} data-size={size} data-color={c}>
+        {children}
+      </div>
+    ),
   };
 });
 
@@ -371,6 +392,399 @@ describe('Field', () => {
     });
   });
 
+  describe('Textarea (text type)', () => {
+    it('should render Textarea for text type', () => {
+      const field = {
+        id: 'bio',
+        type: 'text',
+        label: 'Biography',
+        help_text: 'Enter your biography',
+        default: '',
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Biography')).toBeInTheDocument();
+      expect(screen.getByText('Enter your biography')).toBeInTheDocument();
+    });
+
+    it('should use provided value', () => {
+      const field = {
+        id: 'bio',
+        type: 'text',
+        label: 'Biography',
+        default: '',
+      };
+
+      render(<Field field={field} value="My bio" onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Biography')).toHaveValue('My bio');
+    });
+
+    it('should use default value when value is null', () => {
+      const field = {
+        id: 'bio',
+        type: 'text',
+        label: 'Biography',
+        default: 'Default bio',
+      };
+
+      render(<Field field={field} value={null} onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Biography')).toHaveValue('Default bio');
+    });
+
+    it('should call onChange with field id and value', () => {
+      const field = {
+        id: 'bio',
+        type: 'text',
+        label: 'Biography',
+        default: '',
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      fireEvent.change(screen.getByLabelText('Biography'), {
+        target: { value: 'New bio text' },
+      });
+
+      expect(mockOnChange).toHaveBeenCalledWith('bio', 'New bio text');
+    });
+
+    it('should render with placeholder', () => {
+      const field = {
+        id: 'bio',
+        type: 'text',
+        label: 'Biography',
+        placeholder: 'Enter your bio here...',
+        default: '',
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Biography')).toHaveAttribute(
+        'placeholder',
+        'Enter your bio here...'
+      );
+    });
+  });
+
+  describe('Info type', () => {
+    it('should render info with label and description', () => {
+      const field = {
+        id: 'info1',
+        type: 'info',
+        label: 'Important Information',
+        description: 'This is important info',
+      };
+
+      render(<Field field={field} value={null} onChange={mockOnChange} />);
+
+      expect(screen.getByText('Important Information')).toBeInTheDocument();
+      expect(screen.getByText('This is important info')).toBeInTheDocument();
+    });
+
+    it('should render info with only description', () => {
+      const field = {
+        id: 'info2',
+        type: 'info',
+        description: 'Just a description',
+      };
+
+      render(<Field field={field} value={null} onChange={mockOnChange} />);
+
+      expect(screen.getByText('Just a description')).toBeInTheDocument();
+    });
+
+    it('should render info with only label', () => {
+      const field = {
+        id: 'info3',
+        type: 'info',
+        label: 'Just a label',
+      };
+
+      render(<Field field={field} value={null} onChange={mockOnChange} />);
+
+      expect(screen.getByText('Just a label')).toBeInTheDocument();
+    });
+
+    it('should prioritize help_text over description', () => {
+      const field = {
+        id: 'info4',
+        type: 'info',
+        label: 'Title',
+        help_text: 'Help text takes priority',
+        description: 'This should not appear',
+      };
+
+      render(<Field field={field} value={null} onChange={mockOnChange} />);
+
+      expect(screen.getByText('Help text takes priority')).toBeInTheDocument();
+      expect(screen.queryByText('This should not appear')).not.toBeInTheDocument();
+    });
+
+    it('should use field.value if no help_text or description', () => {
+      const field = {
+        id: 'info5',
+        type: 'info',
+        label: 'Title',
+        value: 'Value text',
+      };
+
+      render(<Field field={field} value={null} onChange={mockOnChange} />);
+
+      expect(screen.getByText('Value text')).toBeInTheDocument();
+    });
+
+    it('should not call onChange for info type', () => {
+      const field = {
+        id: 'info6',
+        type: 'info',
+        label: 'Read-only Info',
+        description: 'Cannot be changed',
+      };
+
+      render(<Field field={field} value={null} onChange={mockOnChange} />);
+
+      expect(mockOnChange).not.toHaveBeenCalled();
+    });
+  });
+
+  describe('Password input type', () => {
+    it('should render password input when input_type is password', () => {
+      const field = {
+        id: 'password',
+        type: 'string',
+        label: 'Password',
+        input_type: 'password',
+        default: '',
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Password')).toHaveAttribute('type', 'password');
+    });
+
+    it('should render text input when input_type is not password', () => {
+      const field = {
+        id: 'username',
+        type: 'string',
+        label: 'Username',
+        input_type: 'text',
+        default: '',
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Username')).toHaveAttribute('type', 'text');
+    });
+
+    it('should default to text input when input_type is undefined', () => {
+      const field = {
+        id: 'email',
+        type: 'string',
+        label: 'Email',
+        default: '',
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Email')).toHaveAttribute('type', 'text');
+    });
+  });
+
+  describe('Description priority', () => {
+    it('should prioritize help_text over description', () => {
+      const field = {
+        id: 'test',
+        type: 'string',
+        label: 'Test',
+        help_text: 'Help text',
+        description: 'Description text',
+        default: '',
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      expect(screen.getByText('Help text')).toBeInTheDocument();
+      expect(screen.queryByText('Description text')).not.toBeInTheDocument();
+    });
+
+    it('should use description when help_text is not provided', () => {
+      const field = {
+        id: 'test',
+        type: 'string',
+        label: 'Test',
+        description: 'Description text',
+        default: '',
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      expect(screen.getByText('Description text')).toBeInTheDocument();
+    });
+
+    it('should use field.value when neither help_text nor description provided', () => {
+      const field = {
+        id: 'test',
+        type: 'string',
+        label: 'Test',
+        value: 'Value text',
+        default: '',
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      expect(screen.getByText('Value text')).toBeInTheDocument();
+    });
+
+    it('should not show description when all are undefined', () => {
+      const field = {
+        id: 'test',
+        type: 'string',
+        label: 'Test',
+        default: '',
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Test')).toBeInTheDocument();
+      // No description should be present
+    });
+  });
+
+  describe('Placeholder handling', () => {
+    it('should render placeholder for TextInput', () => {
+      const field = {
+        id: 'name',
+        type: 'string',
+        label: 'Name',
+        placeholder: 'Enter your name',
+        default: '',
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Name')).toHaveAttribute(
+        'placeholder',
+        'Enter your name'
+      );
+    });
+
+    it('should render placeholder for NumberInput', () => {
+      const field = {
+        id: 'age',
+        type: 'number',
+        label: 'Age',
+        placeholder: 'Enter your age',
+        default: 0,
+      };
+
+      render(<Field field={field} value={null} onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Age')).toHaveAttribute(
+        'placeholder',
+        'Enter your age'
+      );
+    });
+
+    it('should render placeholder for Select', () => {
+      const field = {
+        id: 'country',
+        type: 'select',
+        label: 'Country',
+        placeholder: 'Select a country',
+        default: '',
+        options: [
+          { value: 'us', label: 'United States' },
+          { value: 'ca', label: 'Canada' },
+        ],
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Country')).toHaveAttribute(
+        'placeholder',
+        'Select a country'
+      );
+    });
+
+    it('should render placeholder for Textarea', () => {
+      const field = {
+        id: 'bio',
+        type: 'text',
+        label: 'Biography',
+        placeholder: 'Tell us about yourself',
+        default: '',
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Biography')).toHaveAttribute(
+        'placeholder',
+        'Tell us about yourself'
+      );
+    });
+  });
+
+  describe('Edge cases', () => {
+    it('should handle empty string default value', () => {
+      const field = {
+        id: 'test',
+        type: 'string',
+        label: 'Test',
+        default: '',
+      };
+
+      render(<Field field={field} value={null} onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Test')).toHaveValue('');
+    });
+
+    it('should handle 0 as valid number value', () => {
+      const field = {
+        id: 'count',
+        type: 'number',
+        label: 'Count',
+        default: 10,
+      };
+
+      render(<Field field={field} value={0} onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Count')).toHaveValue(0);
+    });
+
+    it('should handle false as valid boolean value', () => {
+      const field = {
+        id: 'enabled',
+        type: 'boolean',
+        label: 'Enabled',
+        default: true,
+      };
+
+      render(<Field field={field} value={false} onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Enabled')).not.toBeChecked();
+    });
+
+    it('should handle empty string as valid select value', () => {
+      const field = {
+        id: 'status',
+        type: 'select',
+        label: 'Status',
+        default: 'active',
+        options: [
+          { value: '', label: 'None' },
+          { value: 'active', label: 'Active' },
+        ],
+      };
+
+      render(<Field field={field} value="" onChange={mockOnChange} />);
+
+      expect(screen.getByLabelText('Status')).toHaveValue('');
+    });
+  });
+
   describe('Default fallback', () => {
     it('should render TextInput for unknown type', () => {
       const field = {
diff --git a/frontend/src/components/__tests__/GuideRow.test.jsx b/frontend/src/components/__tests__/GuideRow.test.jsx
index 3f103305..8dc18eaf 100644
--- a/frontend/src/components/__tests__/GuideRow.test.jsx
+++ b/frontend/src/components/__tests__/GuideRow.test.jsx
@@ -28,6 +28,18 @@ vi.mock('@mantine/core', async () => {
   };
 });
 
+// Helper function to create programs at specific times
+const createProgramAtTime = (id, startHour, durationMinutes) => {
+  const timelineStart = new Date('2024-01-01T00:00:00Z');
+  const startMs = timelineStart.getTime() + startHour * 60 * 60 * 1000;
+  return {
+    id,
+    title: `Program ${id}`,
+    startMs,
+    endMs: startMs + durationMinutes * 60 * 1000,
+  };
+};
+
 describe('GuideRow', () => {
   const mockChannel = {
     id: 'channel-1',
@@ -64,6 +76,9 @@ describe('GuideRow', () => {
     )),
     handleLogoClick: vi.fn(),
     contentWidth: 1920,
+    guideScrollLeftRef: { current: 0 },
+    viewportWidth: 1920,
+    timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
   };
 
   const mockStyle = {
@@ -160,24 +175,26 @@ describe('GuideRow', () => {
 
   describe('Programs Rendering', () => {
     it('should render programs when channel has programs', () => {
-      render(
-        <GuideRow index={0} style={mockStyle} data={mockData} />
-      );
+      // Create program at hour 0 (definitely within viewport at scrollLeft 0)
+      const visibleProgram = createProgramAtTime('program-1', 0, 60);
 
-      expect(screen.getByTestId(`program-${mockProgram.id}`)).toBeInTheDocument();
-      expect(screen.getByText('Test Program')).toBeInTheDocument();
-      expect(mockData.renderProgram).toHaveBeenCalledWith(
-        mockProgram,
-        undefined,
-        mockChannel
-      );
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, [visibleProgram]]]),
+      };
+
+      render(<GuideRow index={0} style={mockStyle} data={data} />);
+
+      expect(screen.getByTestId('program-program-1')).toBeInTheDocument();
+      expect(mockData.renderProgram).toHaveBeenCalledWith(visibleProgram, undefined, mockChannel);
     });
 
     it('should render multiple programs', () => {
       const programs = [
-        mockProgram,
-        { ...mockProgram, id: 'program-2', title: 'Another Program' },
+        createProgramAtTime('prog-1', 0, 60),
+        createProgramAtTime('prog-2', 1, 30),
       ];
+
       const data = {
         ...mockData,
         programsByChannelId: new Map([[mockChannel.id, programs]]),
@@ -185,9 +202,8 @@ describe('GuideRow', () => {
 
       render(<GuideRow index={0} style={mockStyle} data={data} />);
 
-      expect(screen.getByText('Test Program')).toBeInTheDocument();
-      expect(screen.getByText('Another Program')).toBeInTheDocument();
-      expect(mockData.renderProgram).toHaveBeenCalledTimes(2);
+      expect(screen.getByTestId('program-prog-1')).toBeInTheDocument();
+      expect(screen.getByTestId('program-prog-2')).toBeInTheDocument();
     });
 
     it('should render placeholder when channel has no programs', () => {
@@ -199,7 +215,7 @@ describe('GuideRow', () => {
       render(<GuideRow index={0} style={mockStyle} data={data} />);
 
       const placeholders = screen.getAllByText('No program data');
-      expect(placeholders.length).toBe(Math.ceil(24 / 2));
+      expect(placeholders.length).toBeGreaterThan(0);
     });
 
     it('should render placeholder when programsByChannelId does not contain channel', () => {
@@ -211,7 +227,7 @@ describe('GuideRow', () => {
       render(<GuideRow index={0} style={mockStyle} data={data} />);
 
       const placeholders = screen.getAllByText('No program data');
-      expect(placeholders.length).toBe(Math.ceil(24 / 2));
+      expect(placeholders.length).toBeGreaterThan(0);
     });
 
     it('should position placeholder programs correctly', () => {
@@ -252,12 +268,10 @@ describe('GuideRow', () => {
     });
 
     it('should show play icon on hover', () => {
-      const data = {
-        ...mockData,
-        hoveredChannelId: mockChannel.id,
-      };
+      render(<GuideRow index={0} style={mockStyle} data={mockData} />);
 
-      render(<GuideRow index={0} style={mockStyle} data={data} />);
+      const logo = screen.getByAltText('Test Channel').closest('.channel-logo');
+      fireEvent.mouseEnter(logo);
 
       expect(screen.getByTestId('play-icon')).toBeInTheDocument();
     });
@@ -269,28 +283,6 @@ describe('GuideRow', () => {
 
       expect(screen.queryByTestId('play-icon')).not.toBeInTheDocument();
     });
-
-    it('should call setHoveredChannelId on mouse enter', () => {
-      render(
-        <GuideRow index={0} style={mockStyle} data={mockData} />
-      );
-
-      const logo = screen.getByAltText('Test Channel').closest('.channel-logo');
-      fireEvent.mouseEnter(logo);
-
-      expect(mockData.setHoveredChannelId).toHaveBeenCalledWith(mockChannel.id);
-    });
-
-    it('should call setHoveredChannelId with null on mouse leave', () => {
-      render(
-        <GuideRow index={0} style={mockStyle} data={mockData} />
-      );
-
-      const logo = screen.getByAltText('Test Channel').closest('.channel-logo');
-      fireEvent.mouseLeave(logo);
-
-      expect(mockData.setHoveredChannelId).toHaveBeenCalledWith(null);
-    });
   });
 
   describe('Layout and Styling', () => {
@@ -332,4 +324,392 @@ describe('GuideRow', () => {
       expect(imageContainer).toHaveAttribute('h', `${customHeight - 32}px`);
     });
   });
+
+  describe('Horizontal Viewport Culling', () => {
+    it('should only render programs visible in viewport', () => {
+      const programs = [
+        createProgramAtTime('prog-1', 0, 60),   // Hour 0
+        createProgramAtTime('prog-2', 6, 60),   // Hour 6
+        createProgramAtTime('prog-3', 12, 60),  // Hour 12
+        createProgramAtTime('prog-4', 18, 60),  // Hour 18
+      ];
+
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, programs]]),
+        guideScrollLeftRef: { current: HOUR_WIDTH * 6 }, // Scroll to hour 6
+        viewportWidth: HOUR_WIDTH * 4, // Show 4 hours
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      render(<GuideRow index={0} style={mockStyle} data={data} />);
+
+      // Program at hour 6 should be visible
+      expect(screen.getByTestId('program-prog-2')).toBeInTheDocument();
+
+      // Programs outside viewport + buffer should not be rendered
+      expect(mockData.renderProgram).toHaveBeenCalledTimes(1);
+    });
+
+    it('should render programs within buffer zone', () => {
+      const programs = [
+        createProgramAtTime('prog-1', 0, 60),
+        createProgramAtTime('prog-2', 1, 60),
+      ];
+
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, programs]]),
+        guideScrollLeftRef: { current: HOUR_WIDTH * 2 },
+        viewportWidth: HOUR_WIDTH * 2,
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      render(<GuideRow index={0} style={mockStyle} data={data} />);
+
+      // Programs within H_BUFFER (600px) should be rendered
+      const renderedPrograms = mockData.renderProgram.mock.calls.map(
+        call => call[0]
+      );
+
+      expect(renderedPrograms.length).toBeGreaterThan(0);
+    });
+
+    it('should not render programs completely outside viewport and buffer', () => {
+      const programs = [
+        createProgramAtTime('prog-far-left', 0, 60),
+        createProgramAtTime('prog-visible', 10, 60),
+        createProgramAtTime('prog-far-right', 22, 60),
+      ];
+
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, programs]]),
+        guideScrollLeftRef: { current: HOUR_WIDTH * 10 },
+        viewportWidth: HOUR_WIDTH * 2,
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      render(<GuideRow index={0} style={mockStyle} data={data} />);
+
+      const renderedPrograms = mockData.renderProgram.mock.calls.map(
+        call => call[0].id
+      );
+
+      // Only visible program should be rendered
+      expect(renderedPrograms).toContain('prog-visible');
+      expect(renderedPrograms).not.toContain('prog-far-left');
+      expect(renderedPrograms).not.toContain('prog-far-right');
+    });
+
+    it('should handle edge case where program spans viewport boundary', () => {
+      const programs = [
+        createProgramAtTime('prog-spanning', 5, 180), // 3-hour program
+      ];
+
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, programs]]),
+        guideScrollLeftRef: { current: HOUR_WIDTH * 6 },
+        viewportWidth: HOUR_WIDTH * 2,
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      render(<GuideRow index={0} style={mockStyle} data={data} />);
+
+      // Program spanning viewport should be visible
+      expect(screen.getByTestId('program-prog-spanning')).toBeInTheDocument();
+    });
+
+    it('should update visible programs when scroll position changes', () => {
+      const programs = [
+        createProgramAtTime('prog-1', 0, 60),
+        createProgramAtTime('prog-2', 12, 60),
+      ];
+
+      const scrollRef = { current: 0 };
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, programs]]),
+        guideScrollLeftRef: scrollRef,
+        viewportWidth: HOUR_WIDTH * 4,
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      const { rerender } = render(
+        <GuideRow index={0} style={mockStyle} data={data} />
+      );
+
+      const initialCalls = mockData.renderProgram.mock.calls.length;
+
+      // Scroll to different position
+      scrollRef.current = HOUR_WIDTH * 12;
+      const newData = { ...data, guideScrollLeftRef: scrollRef };
+
+      rerender(<GuideRow index={0} style={mockStyle} data={newData} />);
+
+      // Different programs should be rendered
+      expect(mockData.renderProgram.mock.calls.length).toBeGreaterThan(initialCalls);
+    });
+  });
+
+  describe('Placeholder Culling', () => {
+    it('should only render placeholders visible in viewport', () => {
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, []]]),
+        guideScrollLeftRef: { current: HOUR_WIDTH * 10 },
+        viewportWidth: HOUR_WIDTH * 4,
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      const { container } = render(
+        <GuideRow index={0} style={mockStyle} data={data} />
+      );
+
+      const visiblePlaceholders = screen.getAllByText('No program data');
+
+      // Should render fewer than total placeholders due to culling
+      expect(visiblePlaceholders.length).toBeLessThan(Math.ceil(24 / 2));
+      expect(visiblePlaceholders.length).toBeGreaterThan(0);
+    });
+
+    it('should not render placeholders outside viewport', () => {
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, []]]),
+        guideScrollLeftRef: { current: HOUR_WIDTH * 20 },
+        viewportWidth: HOUR_WIDTH * 2,
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      const { container } = render(
+        <GuideRow index={0} style={mockStyle} data={data} />
+      );
+
+      const visiblePlaceholders = screen.getAllByText('No program data');
+
+      // Near the end of timeline, should show fewer placeholders
+      expect(visiblePlaceholders.length).toBeGreaterThan(0);
+      expect(visiblePlaceholders.length).toBeLessThanOrEqual(3);
+    });
+  });
+
+  describe('Hover State Management', () => {
+    it('should show play icon on mouse enter', () => {
+      render(<GuideRow index={0} style={mockStyle} data={mockData} />);
+
+      const logoContainer = screen.getByAltText('Test Channel').closest('.channel-logo');
+
+      expect(screen.queryByTestId('play-icon')).not.toBeInTheDocument();
+
+      fireEvent.mouseEnter(logoContainer);
+
+      expect(screen.getByTestId('play-icon')).toBeInTheDocument();
+    });
+
+    it('should hide play icon on mouse leave', () => {
+      render(<GuideRow index={0} style={mockStyle} data={mockData} />);
+
+      const logoContainer = screen.getByAltText('Test Channel').closest('.channel-logo');
+
+      fireEvent.mouseEnter(logoContainer);
+      expect(screen.getByTestId('play-icon')).toBeInTheDocument();
+
+      fireEvent.mouseLeave(logoContainer);
+      expect(screen.queryByTestId('play-icon')).not.toBeInTheDocument();
+    });
+
+    it('should maintain hover state independently per row', () => {
+      const data = {
+        ...mockData,
+        filteredChannels: [mockChannel, { ...mockChannel, id: 'channel-2', name: 'Channel 2' }],
+      };
+
+      // Render both rows separately
+      const { container: container1 } = render(
+        <GuideRow index={0} style={mockStyle} data={data} />
+      );
+      const { container: container2 } = render(
+        <GuideRow index={1} style={{ ...mockStyle, top: PROGRAM_HEIGHT }} data={data} />
+      );
+
+      // Hover over first row
+      const logo1 = container1.querySelector('.channel-logo');
+      fireEvent.mouseEnter(logo1);
+
+      // First row should show play icon
+      expect(container1.querySelector('[data-testid="play-icon"]')).toBeInTheDocument();
+
+      // Second row should not show play icon
+      expect(container2.querySelector('[data-testid="play-icon"]')).not.toBeInTheDocument();
+    });
+
+  });
+
+  describe('Program Time Positioning', () => {
+    const createTimedProgram = (startHour, durationMinutes) => {
+      const timelineStart = new Date('2024-01-01T00:00:00Z');
+      const startMs = timelineStart.getTime() + startHour * 60 * 60 * 1000;
+      return {
+        id: `program-${startHour}`,
+        title: `Program at ${startHour}h`,
+        startMs,
+        endMs: startMs + durationMinutes * 60 * 1000,
+      };
+    };
+
+    it('should calculate correct viewport boundaries', () => {
+      const programs = [
+        createTimedProgram(6, 60),
+        createTimedProgram(12, 60),
+      ];
+
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, programs]]),
+        guideScrollLeftRef: { current: HOUR_WIDTH * 8 },
+        viewportWidth: HOUR_WIDTH * 4,
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      render(<GuideRow index={0} style={mockStyle} data={data} />);
+
+      // Both programs should be rendered since they're within viewport range
+      expect(mockData.renderProgram).toHaveBeenCalled();
+    });
+
+    it('should handle programs at timeline boundaries', () => {
+      const programs = [
+        createTimedProgram(0, 60),      // Start of timeline
+        createTimedProgram(23, 60),     // End of timeline
+      ];
+
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, programs]]),
+        guideScrollLeftRef: { current: 0 },
+        viewportWidth: HOUR_WIDTH * 24,
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      render(<GuideRow index={0} style={mockStyle} data={data} />);
+
+      expect(screen.getByText('Program at 0h')).toBeInTheDocument();
+      expect(screen.getByText('Program at 23h')).toBeInTheDocument();
+    });
+
+    it('should handle very short programs', () => {
+      const programs = [
+        createTimedProgram(12, 5), // 5-minute program
+      ];
+
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, programs]]),
+        guideScrollLeftRef: { current: HOUR_WIDTH * 12 },
+        viewportWidth: HOUR_WIDTH * 2,
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      render(<GuideRow index={0} style={mockStyle} data={data} />);
+
+      expect(screen.getByTestId('program-program-12')).toBeInTheDocument();
+    });
+
+    it('should handle very long programs', () => {
+      const programs = [
+        createTimedProgram(6, 360), // 6-hour program
+      ];
+
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, programs]]),
+        guideScrollLeftRef: { current: HOUR_WIDTH * 8 },
+        viewportWidth: HOUR_WIDTH * 2,
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      render(<GuideRow index={0} style={mockStyle} data={data} />);
+
+      // Long program spanning viewport should be visible
+      expect(screen.getByTestId('program-program-6')).toBeInTheDocument();
+    });
+  });
+
+  describe('Edge Cases', () => {
+    it('should handle empty programsByChannelId gracefully', () => {
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map(),
+        guideScrollLeftRef: { current: 0 },
+        viewportWidth: HOUR_WIDTH * 4,
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      render(<GuideRow index={0} style={mockStyle} data={data} />);
+
+      expect(screen.getAllByText('No program data').length).toBeGreaterThan(0);
+    });
+
+    it('should handle zero viewport width', () => {
+      const programs = [mockProgram];
+
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, programs]]),
+        guideScrollLeftRef: { current: 0 },
+        viewportWidth: 0,
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      render(<GuideRow index={0} style={mockStyle} data={data} />);
+
+      // Should still render due to buffer
+      expect(screen.getByTestId('guide-row')).toBeInTheDocument();
+    });
+
+    it('should handle negative scroll position', () => {
+      const programs = [createProgramAtTime('prog-1', 0, 60)];
+
+      const data = {
+        ...mockData,
+        programsByChannelId: new Map([[mockChannel.id, programs]]),
+        guideScrollLeftRef: { current: -100 },
+        viewportWidth: HOUR_WIDTH * 4,
+        timelineStartMs: new Date('2024-01-01T00:00:00Z').getTime(),
+      };
+
+      render(<GuideRow index={0} style={mockStyle} data={data} />);
+
+      expect(screen.getByTestId('guide-row')).toBeInTheDocument();
+    });
+
+    it('should handle row index out of bounds', () => {
+      const data = {
+        ...mockData,
+        filteredChannels: [mockChannel],
+      };
+
+      const { container } = render(
+        <GuideRow index={999} style={mockStyle} data={data} />
+      );
+
+      expect(container.firstChild).toBeNull();
+    });
+
+    it('should memoize component to prevent unnecessary re-renders', () => {
+      const { rerender } = render(
+        <GuideRow index={0} style={mockStyle} data={mockData} />
+      );
+
+      const renderCount = mockData.renderProgram.mock.calls.length;
+
+      // Re-render with same props
+      rerender(<GuideRow index={0} style={mockStyle} data={mockData} />);
+
+      // Should not cause additional renders due to React.memo
+      expect(mockData.renderProgram.mock.calls.length).toBe(renderCount);
+    });
+  });
 });
diff --git a/frontend/src/components/__tests__/Sidebar.test.jsx b/frontend/src/components/__tests__/Sidebar.test.jsx
index 341d0c32..d3163b1d 100644
--- a/frontend/src/components/__tests__/Sidebar.test.jsx
+++ b/frontend/src/components/__tests__/Sidebar.test.jsx
@@ -16,6 +16,10 @@ vi.mock('../../utils', () => ({
   copyToClipboard: vi.fn(),
 }));
 
+vi.mock('../NotificationCenter', () => ({
+  default: () => <div data-testid="notification-center">Notification Center</div>,
+}));
+
 // Mock lucide-react icons
 vi.mock('lucide-react', () => ({
   ListOrdered: ({ onClick }) => <div data-testid="list-ordered-icon" onClick={onClick} />,
@@ -30,6 +34,12 @@ vi.mock('lucide-react', () => ({
   LogOut: ({ onClick }) => <div data-testid="logout-icon" onClick={onClick} />,
   User: ({ onClick }) => <div data-testid="user-icon" onClick={onClick} />,
   FileImage: ({ onClick }) => <div data-testid="file-image-icon" onClick={onClick} />,
+  Webhook: () => <div data-testid="webhook-icon" />,
+  Logs: () => <div data-testid="logs-icon" />,
+  ChevronDown: () => <div data-testid="chevron-down-icon" />,
+  ChevronRight: () => <div data-testid="chevron-right-icon" />,
+  MonitorCog: () => <div data-testid="monitor-cog-icon" />,
+  Blocks: () => <div data-testid="blocks-icon" />,
 }));
 
 // Mock UserForm component
@@ -85,14 +95,11 @@ vi.mock('@mantine/core', async () => {
         {children}
       </nav>
     ),
+    ScrollArea: ({ children }) => <div>{children}</div>,
   };
 });
 
-const mockChannels = {
-  'channel-1': { id: 'channel-1', name: 'Channel 1' },
-  'channel-2': { id: 'channel-2', name: 'Channel 2' },
-  'channel-3': { id: 'channel-3', name: 'Channel 3' },
-};
+const mockChannels = [ 'channel-1', 'channel-2', 'channel-3' ];
 
 const mockEnvironment = {
   public_ip: '192.168.1.1',
@@ -182,7 +189,7 @@ describe('Sidebar', () => {
   });
 
   describe('Navigation Links - Admin User', () => {
-    it('should render all admin navigation items', () => {
+    it('should render all admin navigation items', async () => {
       renderSidebar();
 
       expect(screen.getByText('Channels')).toBeInTheDocument();
@@ -192,9 +199,16 @@ describe('Sidebar', () => {
       expect(screen.getByText('DVR')).toBeInTheDocument();
       expect(screen.getByText('Stats')).toBeInTheDocument();
       expect(screen.getByText('Plugins')).toBeInTheDocument();
-      expect(screen.getByText('Users')).toBeInTheDocument();
-      expect(screen.getByText('Logo Manager')).toBeInTheDocument();
-      expect(screen.getByText('Settings')).toBeInTheDocument();
+
+      // Expand System group to access Users
+      const systemButton = screen.getByText('System');
+      fireEvent.click(systemButton);
+
+      await waitFor(() => {
+        expect(screen.getByText('Users')).toBeInTheDocument();
+        expect(screen.getByText('Logo Manager')).toBeInTheDocument();
+        expect(screen.getByText('Settings')).toBeInTheDocument();
+      });
     });
 
     it('should display channel count badge', () => {
@@ -452,4 +466,163 @@ describe('Sidebar', () => {
       expect(flag).toBeInTheDocument();
     });
   });
+
+  describe('NavGroup Component', () => {
+    it('should render Integrations group with children collapsed by default', () => {
+      renderSidebar();
+
+      expect(screen.getByText('Integrations')).toBeInTheDocument();
+      expect(screen.queryByText('Connections')).not.toBeInTheDocument();
+      expect(screen.queryByText('Logs')).not.toBeInTheDocument();
+    });
+
+    it('should expand Integrations group when clicked', async () => {
+      renderSidebar();
+
+      const integrationsGroup = screen.getByText('Integrations').closest('button');
+      fireEvent.click(integrationsGroup);
+
+      await waitFor(() => {
+        expect(screen.getByText('Connections')).toBeInTheDocument();
+        expect(screen.getByText('Logs')).toBeInTheDocument();
+      });
+    });
+
+    it('should collapse Integrations group when clicked again', async () => {
+      renderSidebar();
+
+      const integrationsGroup = screen.getByText('Integrations').closest('button');
+
+      // Expand
+      fireEvent.click(integrationsGroup);
+      await waitFor(() => {
+        expect(screen.getByText('Connections')).toBeInTheDocument();
+      });
+
+      // Collapse
+      fireEvent.click(integrationsGroup);
+      await waitFor(() => {
+        expect(screen.queryByText('Connections')).not.toBeInTheDocument();
+        expect(screen.queryByText('Logs')).not.toBeInTheDocument();
+      });
+    });
+
+    it('should render System group with children collapsed by default', () => {
+      renderSidebar();
+
+      expect(screen.getByText('System')).toBeInTheDocument();
+      expect(screen.queryByText('Users')).not.toBeInTheDocument();
+      expect(screen.queryByText('Logo Manager')).not.toBeInTheDocument();
+    });
+
+    it('should expand System group when clicked', async () => {
+      renderSidebar();
+
+      const systemGroup = screen.getByText('System').closest('button');
+      fireEvent.click(systemGroup);
+
+      await waitFor(() => {
+        expect(screen.getByText('Users')).toBeInTheDocument();
+        expect(screen.getByText('Logo Manager')).toBeInTheDocument();
+        expect(screen.getByText('Settings')).toBeInTheDocument();
+      });
+    });
+
+    it('should hide group label when collapsed sidebar', () => {
+      renderSidebar({ collapsed: true });
+
+      expect(screen.queryByText('Integrations')).not.toBeInTheDocument();
+      expect(screen.queryByText('System')).not.toBeInTheDocument();
+    });
+
+    it('should not show multiple groups collapsed when both expanded', async () => {
+      renderSidebar();
+
+      const integrationsGroup = screen.getByText('Integrations').closest('button');
+      const systemGroup = screen.getByText('System').closest('button');
+
+      // Expand Integrations
+      fireEvent.click(integrationsGroup);
+      await waitFor(() => {
+        expect(screen.getByText('Connections')).toBeInTheDocument();
+      });
+
+      // Expand System (Integrations should remain expanded)
+      fireEvent.click(systemGroup);
+      await waitFor(() => {
+        expect(screen.getByText('Users')).toBeInTheDocument();
+        expect(screen.getByText('Connections')).toBeInTheDocument();
+      });
+    });
+  });
+
+  describe('NotificationCenter Integration', () => {
+    it('should render NotificationCenter when authenticated and expanded', () => {
+      renderSidebar();
+
+      expect(screen.getByTestId('notification-center')).toBeInTheDocument();
+    });
+
+    it('should render NotificationCenter when authenticated and collapsed', () => {
+      renderSidebar({ collapsed: true });
+
+      expect(screen.getByTestId('notification-center')).toBeInTheDocument();
+    });
+
+    it('should not render NotificationCenter when not authenticated', () => {
+      useAuthStore.mockImplementation((selector) => {
+        const state = {
+          isAuthenticated: false,
+          user: null,
+          logout: vi.fn(),
+        };
+        return selector(state);
+      });
+
+      renderSidebar();
+
+      expect(screen.queryByTestId('notification-center')).not.toBeInTheDocument();
+    });
+
+    it('should not render NotificationCenter when not authenticated and collapsed', () => {
+      useAuthStore.mockImplementation((selector) => {
+        const state = {
+          isAuthenticated: false,
+          user: null,
+          logout: vi.fn(),
+        };
+        return selector(state);
+      });
+
+      renderSidebar({ collapsed: true });
+
+      expect(screen.queryByTestId('notification-center')).not.toBeInTheDocument();
+    });
+  });
+
+  describe('Channel Count Badge', () => {
+    it('should display 0 when no channels exist', () => {
+      useChannelsStore.mockReturnValue({});
+
+      renderSidebar();
+
+      expect(screen.getByText('(0)')).toBeInTheDocument();
+    });
+
+    it('should handle null channelIds gracefully', () => {
+      useChannelsStore.mockReturnValue(null);
+
+      renderSidebar();
+
+      expect(screen.getByText('(0)')).toBeInTheDocument();
+    });
+
+    it('should handle array of channel IDs', () => {
+      useChannelsStore.mockReturnValue(['channel-1', 'channel-2', 'channel-3']);
+
+      renderSidebar();
+
+      expect(screen.getByText('(3)')).toBeInTheDocument();
+    });
+  });
 });