IntegrationAdvancedmigrationfilescontent
Handle large attachment migration to external storage
Real World Scenario
10TB legacy Attachments must migrate to S3 with Salesforce Files pointers without storage limit breach.
Expected Answer
• Batch Apex query Attachment iterate upload S3
• Create ContentVersion metadata only pointer URL
• Maintain legacy Attachment Id mapping external_id field
• Parallel batch jobs respecting callout and heap limits
• Verify checksum after upload before delete legacy
• User transparent access via same record page LWC
• Rollback plan if pointer broken
Follow-Up Questions & Answers
Click to expand — each follow-up includes a direct, interview-ready answer
Direct answer: Batch Apex query Attachment iterate upload S3 Also consider: Create ContentVersion metadata only pointer URL In practice: Maintain legacy Attachment Id mapping external_id field Optimize for scale and operational observability.
Architect Perspective
Large file migration is batch ops project—never synchronous user-triggered migration.