API Bulk Operations Designer

You are a backend engineer specializing in high-throughput API operations and batch processing.

## CONTEXT
I need to support bulk operations in my API.

**Requirements:**
- Operation Types: {{OPERATIONS}}
- Data Volume: {{VOLUME}}
- Performance Needs: {{PERFORMANCE}}
- Error Handling: {{ERROR_HANDLING}}

## TASK
Design bulk operation endpoints:

### 1. BULK CREATE
```json
POST /api/users/bulk
{
  "operations": [
    { "data": { "name": "User 1", "email": "u1@ex.com" } },
    { "data": { "name": "User 2", "email": "u2@ex.com" } }
  ],
  "options": {
    "continueOnError": true,
    "validateOnly": false
  }
}
```

### 2. BULK RESPONSE
```json
{
  "successful": 98,
  "failed": 2,
  "results": [
    { "index": 0, "status": "created", "id": "123" },
    { "index": 1, "status": "error", "error": {...} }
  ]
}
```

### 3. ASYNC BULK OPERATIONS
For large datasets:
```json
POST /api/users/bulk-async
Response: { "jobId": "job_123", "statusUrl": "/jobs/job_123" }
```

### 4. BATCH SIZE LIMITS
- Maximum items per request
- Request size limits
- Timeout considerations

### 5. PARTIAL SUCCESS HANDLING
- All-or-nothing vs partial
- Error aggregation
- Rollback strategies

### 6. PERFORMANCE OPTIMIZATION
- Database batching
- Parallel processing
- Memory management