Apex
Queueable, Batch, and scheduled Apex
Choose asynchronous processing by workload rather than by habit.
By Vishal Verma · Reviewed October 5, 2026
Practice these questions aloud. Give the principle, explain a concrete example, and finish with how you would verify the result.
1. When would you choose Queueable Apex?
Suggested answer: For bounded background work that needs a job ID, complex state, or a controlled sequence of jobs. Monitor AsyncApexJob and design failure recovery. It is queued work, not a guarantee of immediate execution.
Scenario / follow-up: A record save initiates one external synchronization job.
2. When would you choose Batch Apex?
Suggested answer: For large workloads split into processing scopes. Each execute scope runs in a separate transaction. Decide how partial completion, failures, and retries will be reported.
Scenario / follow-up: A nightly reconciliation must process a large record population.
3. What does scheduled Apex add?
Suggested answer: It starts work according to a schedule. It does not automatically make a large workload efficient. A scheduled job can orchestrate the appropriate processing mechanism.
Scenario / follow-up: Consider overlap: what happens if yesterday’s work is still running?
Reviewed October 5, 2026. Check the linked documentation for your org’s API version and supported features.