ApexAdvancedconcurrencylockingmodstamp
Design Apex for optimistic locking with System Modstamp
Real World Scenario
Two reps edit same Opportunity offline mobile; last write wins silently drops first rep discount.
Expected Answer
• Client sends LastModifiedDate or custom version number on save
• Trigger compares SystemModstamp rejecting stale updates with clear error
• UI prompts refresh and merge on conflict
• Optional custom Lock_Version__c incremented each save
• Integration uses If-Unmodified-Since pattern in REST API
• Audit conflicting updates for manager review
• Test concurrent update simulation with parallel futures
Follow-Up Questions & Answers
Click to expand — each follow-up includes a direct, interview-ready answer
Direct answer: Client sends LastModifiedDate or custom version number on save Also consider: Trigger compares SystemModstamp rejecting stale updates with clear error In practice: UI prompts refresh and merge on conflict Optimize for scale and operational observability.
Architect Perspective
Optimistic locking prevents silent data loss—essential for mobile and parallel integrations.