retellai-migration-deep-dive

# Retell AI Migration Deep Dive

## Overview
Comprehensive guide for migrating to or from Retell AI, or major version upgrades.

## Prerequisites
- Current system documentation
- Retell AI SDK installed
- Feature flag infrastructure
- Rollback strategy tested

## Migration Types

| Type | Complexity | Duration | Risk |
|------|-----------|----------|------|
| Fresh install | Low | Days | Low |
| From competitor | Medium | Weeks | Medium |
| Major version | Medium | Weeks | Medium |
| Full replatform | High | Months | High |

## Pre-Migration Assessment

### Step 1: Current State Analysis
```bash
# Document current implementation
find . -name "*.ts" -o -name "*.py" | xargs grep -l "retellai" > retellai-files.txt

# Count integration points
wc -l retellai-files.txt

# Identify dependencies
npm list | grep retellai
pip freeze | grep retellai
```

### Step 2: Data Inventory
```typescript
interface MigrationInventory {
  dataTypes: string[];
  recordCounts: Record<string, number>;
  dependencies: string[];
  integrationPoints: string[];
  customizations: string[];
}

async function assessRetell AIMigration(): Promise<MigrationInventory> {
  return {
    dataTypes: await getDataTypes(),
    recordCounts: await getRecordCounts(),
    dependencies: await analyzeDependencies(),
    integrationPoints: await findIntegrationPoints(),
    customizations: await documentCustomizations(),
  };
}
```

## Migration Strategy: Strangler Fig Pattern

```
Phase 1: Parallel Run
┌─────────────┐     ┌─────────────┐
│   Old       │     │   New       │
│   System    │ ──▶ │  Retell AI   │
│   (100%)    │     │   (0%)      │
└─────────────┘     └─────────────┘

Phase 2: Gradual Shift
┌─────────────┐     ┌─────────────┐
│   Old       │     │   New       │
│   (50%)     │ ──▶ │   (50%)     │
└─────────────┘     └─────────────┘

Phase 3: Complete
┌─────────────┐     ┌─────────────┐
│   Old       │     │   New       │
│   (0%)      │ ──▶ │   (100%)    │
└─────────────┘     └─────────────┘
```

##