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Lesson 5 of 6 · 5–10 minutes including the walkthrough and reflection

Async Apex

Deferring work changes the user experience and operational contract. Decide what must finish now and what can finish later.

The concept

Queueable Apex uses a class implementing Queueable and an execute method. Enqueuing returns a job identifier for tracking. A running queueable job can chain a subsequent job for dependent work. Async execution is not a promise of an immediate completion time; callers need a way to understand pending work and failures.

Worked example

Illustrative workflow:
Request accepts work -> record pending state
Enqueue job -> retain job identifier
Worker performs work -> record outcome
Operator investigates unsuccessful outcomes

The initial response acknowledges accepted work rather than claiming the final result is ready. The job identifier helps connect the request with later processing. If work depends on earlier output, explain the dependency rather than launching independent jobs and assuming their order.

Common mistake

Changing a synchronous operation to async without updating user expectations, completion tracking or recovery behavior.

Interview angle

Justify the execution model from volume, dependency and response-time requirements. Explain how a person can tell whether the work finished.

Pause and apply

Sketch an operation with one immediate decision and one deferred activity. Define the information shown to the user while it is pending. Write down how an operator would locate a failed job. Use the linked scenario to compare tools rather than treating Queueable as the answer to every asynchronous workload.

Official references

Control Processes with Queueable Apex (opens in a new tab)

Reviewed 2026-09-13. Examples are illustrative; no code is executed here.

Apply it in practice

Choose the Right Async Apex Tool

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