sf-async-apex-patterns

Use Queueable as the default async choice for complex arguments, ordered steps, and callouts; use Batch Apex for record-set processing above 50,000 rows with per-chunk limit resets and error isolation. Batch supports up to 50 million records via QueryLocator, while Queueable chains one child per job.

Attach a Transaction Finalizer with System.attachFinalizer inside the queueable execute method. The finalizer runs in its own transaction, receives the failure exception via FinalizerContext, and can re-enqueue the failed job up to five consecutive times.

Yes, Batch Apex supports callouts when the class implements Database.AllowsCallouts, with a limit of 100 callouts per start, execute, or finish method. Because chunks can re-run after service maintenance, any callout inside execute must be idempotent.

The subscriber likely exceeded the retry cap after throwing EventBus.RetryableException nine times, moving it to the Error state and disconnecting it. Query EventBusSubscriber for Status != 'Running', fix and save the trigger to resume; events published during the outage are lost.

A queueable can enqueue only one child job, and Developer or Trial orgs cap chained stack depth at 5. Bound chains with AsyncOptions.MaximumQueueableStackDepth and check AsyncInfo.getCurrentQueueableStackDepth before re-enqueuing to avoid burning the daily async limit.

Deployment fails with 'This schedulable class has jobs pending or in progress' when an active CronTrigger references the class. Abort the scheduled job with System.abortJob, deploy the class, then reschedule it.