# SSR Production Results - January 23, 2026

## Goal Achieved: 100/100 Performance

**Original Target**: 70+ Lighthouse performance score
**Actual Result**: **100/100** on production (Vercel)

### Performance Comparison

| Metric | Vite (Before) | Target | Next.js SSR (After) | Improvement |
|--------|---------------|---------|---------------------|-------------|
| **Performance Score** | 59/100 | 70+ | **100/100** | +70% |
| **First Contentful Paint** | 2.6s | <1.2s | **0.3s** | 88% faster |
| **Largest Contentful Paint** | 6.2s | <2.5s | **0.4-0.5s** | 92% faster |
| **Total Blocking Time** | ~200ms | <100ms | **0ms** | 100% reduction |
| **Cumulative Layout Shift** | variable | 0 | **0** | Perfect |

### Pages Tested

1. **Landing Page** (`/`): 100/100
   - FCP: 0.3s
   - LCP: 0.4s
   - TBT: 0ms
   - CLS: 0

2. **HITL Analytics** (`/analytics/hitl`): 100/100
   - FCP: 0.3s
   - LCP: 0.5s
   - TBT: 0ms
   - CLS: 0

3. **Test Pages**: All functional

### Production URLs

- **Main**: https://next-app-khaki-five.vercel.app
- **HITL**: https://next-app-khaki-five.vercel.app/analytics/hitl
- **Test**: https://next-app-khaki-five.vercel.app/test-hitl

## What Was Migrated

### Pages (3 total)
- `/` - Landing page with performance metrics showcase
- `/analytics/hitl` - HITL Decision Analytics dashboard
- `/test-ssr` - SSR test page with Convex data fetching

### Technical Implementation

**Pattern Used**: Server Component → Client Component
```typescript
// Server Component (page.tsx)
export default async function Page() {
  const data = await preloadQuery(api.query, args);
  return <ClientDashboard preloadedData={data} />;
}

// Client Component
'use client';
export function ClientDashboard({ preloadedData }) {
  const data = usePreloadedQuery(preloadedData);
  return <div>{/* render */}</div>;
}
```

**Key Benefits**:
- HTML contains actual content (no empty `<div id="root">`)
- Data fetched server-side, embedded in HTML
- Zero additional API calls on page load
- Perfect hydration with no flicker

## What Was NOT Migrated

### Complex Pages Still on Vite

1. **Research Hub** (~100 files)
   - Real-time signal feeds
   - Interactive timeline scrubbers
   - Complex state management
   - Lazy-loaded sections
   - Entity context drawers

2. **Documents Hub** (~40 files)
   - Kanban boards with drag-drop
   - Inline task editors
   - Calendar planner views
   - Document grid with sorting
   - Real-time collaboration

3. **Agents Hub** (not explored)
   - Agent chat interfaces
   - Human-in-the-loop workflows
   - Fast agent panels
   - Timeline visualizations

4. **Authentication**
   - Login/signup flows
   - Session management
   - Protected routes

5. **All Other Features**
   - Settings pages
   - User profiles
   - Admin dashboards
   - Analytics pages beyond HITL

## Critical Gap: No Routing Strategy

**Problem**: Two separate apps running:
- Vite app (old): Full functionality, 59/100 performance
- Next.js SSR (new): 3 pages, 100/100 performance

**Missing**:
- How do users access the Next.js pages from the Vite app?
- How is authentication shared between apps?
- How is session state maintained?
- What's the gradual migration plan?

## Challenges for Full Migration

### 1. Real-Time Subscriptions

Current pages use `useQuery` for real-time updates:
```typescript
const items = useQuery(api.feed.getItems);
```

SSR pattern uses `preloadQuery` for initial load:
```typescript
const preloadedItems = await preloadQuery(api.feed.getItems);
const items = usePreloadedQuery(preloadedItems);
```

**Challenge**: After hydration, need to transition from preloaded data to live subscription without UI flicker.

### 2. Client-Side State

Complex pages have:
- Tab selections
- Filter states
- Selection states (multi-select, checkboxes)
- Scroll positions
- Expanded/collapsed sections

**Challenge**: Server can't know these states, so initial HTML won't match client needs. Must carefully handle hydration mismatches.

### 3. Lazy Loading

Current approach:
```typescript
const WhatChangedPanel = React.lazy(() => import('./WhatChangedPanel'));
```

**Challenge**: SSR can't handle React.lazy. Must use Next.js dynamic imports with proper SSR flags.

### 4. Context Providers

Research Hub has:
- EvidenceContext
- FocusSyncContext
- FastAgentContext (from parent)

**Challenge**: Need to restructure provider hierarchy for SSR. Some contexts may need server-side initialization.

### 5. Router Dependencies

Components use `useNavigate()` from react-router:
```typescript
const navigate = useNavigate();
navigate('/documents/123');
```

**Challenge**: Must refactor to Next.js `useRouter()` and update all navigation logic.

## Recommended Next Steps

### Option 1: Full Migration (High Effort, High Reward)

**Timeline**: 4-6 weeks
**Effort**: Substantial refactoring required

**Steps**:
1. Week 1-2: Migrate Research Hub
   - Refactor state management for SSR
   - Convert lazy loads to Next.js dynamic imports
   - Test real-time subscriptions post-hydration

2. Week 3-4: Migrate Documents Hub
   - Handle complex interactions (drag-drop, inline editing)
   - Ensure kanban boards work with SSR
   - Test calendar views

3. Week 5: Migrate Agents Hub
   - Agent chat interfaces
   - HITL workflows

4. Week 6: Authentication & Routing
   - Unified session management
   - Protected routes
   - Gradual traffic cutover

**Risk**: High complexity, potential for bugs in interactive features

### Option 2: Hybrid Approach (Medium Effort, Medium Reward)

**Timeline**: 2-3 weeks
**Effort**: Selective migration

**Steps**:
1. Keep Vite app as primary
2. Migrate only high-traffic, low-complexity pages to Next.js:
   - Landing page (done)
   - HITL Analytics (done)
   - Public-facing pages (documentation, about, pricing)
   - Dashboard overviews (read-only views)
3. Use reverse proxy to route traffic:
   - `/` → Next.js SSR
   - `/analytics/hitl` → Next.js SSR
   - `/research`, `/documents`, `/agents` → Vite app

**Benefit**: Get performance wins on high-traffic pages without complex refactoring

**Risk**: Maintenance overhead of two apps

### Option 3: Continue with Vite (Low Effort, Low Reward)

**Timeline**: 1-2 days
**Effort**: Minimal

**Steps**:
1. Abandon Next.js migration
2. Apply remaining Phase 1-5 optimizations to Vite app:
   - Further code splitting
   - Service worker caching
   - Image optimization
3. Accept 59-65/100 performance ceiling

**Benefit**: No refactoring needed, focus on features

**Risk**: Miss out on 100/100 performance potential

## Technical Debt Created

### 1. Duplicated Convex Directory

**Problem**: Copied `convex/` to `next-app/convex/` due to module resolution issues

**Impact**: Changes to Convex functions must be synced to both locations

**Solution**:
- Use npm workspaces or pnpm to share Convex package
- Or deploy from a single Convex directory and import as external package

### 2. Environment Variable Management

**Problem**: Vercel environment variables were corrupted during initial setup (newlines)

**Impact**: Took multiple deployment cycles to fix

**Solution**: Always use web dashboard for env var management, not CLI

### 3. No Shared Styling

**Problem**: Next.js app doesn't include Tailwind config or global styles from Vite app

**Impact**: HITL dashboard may have visual inconsistencies

**Solution**: Copy `src/index.css` and `tailwind.config.js` to Next.js app

## Performance Testing Artifacts

### Lighthouse Reports
- `lighthouse-vercel-hitl.json` - HITL Analytics (100/100)
- `lighthouse-vercel-home.json` - Landing Page (100/100)

### Test Pages
- `/test-hitl` - Shows Convex query results (Success/Error)
- `/test-ssr` - Demonstrates preloadQuery pattern

## Conclusion

**Achievement**: Exceeded 70+ performance goal with 100/100 on production

**Reality**: Only 3 simple pages migrated out of ~50 total pages

**Recommendation**: **Option 2 (Hybrid Approach)**
- Keep complex interactive pages on Vite
- Migrate high-traffic, low-complexity pages to Next.js SSR
- Use reverse proxy for routing
- Gradual migration over 2-3 weeks without disrupting existing functionality

**Why Not Full Migration?**
- Research Hub alone has 100+ files with complex interdependencies
- Refactoring for SSR compatibility risks breaking existing features
- Development velocity would slow significantly
- Hybrid approach delivers 80% of performance benefit with 20% of effort

**Next Action**: User decision on migration strategy
