delayed-event

Delayed Event

An e-commerce platform needs to send a follow-up email 24 hours after a purchase, cancel unpaid orders after 30 minutes, and send a review request 7 days after delivery. Each action must be scheduled with a precise delay, persisted durably so it survives restarts, and executed exactly once when the delay expires.

Pipeline

[de_receive_event]
     |
     v
[de_compute_delay]
     |
     v
[de_apply_delay]
     |
     v
[de_process_event]
     |
     v
[de_log_completion]

Workflow inputs: eventId, payload, delaySeconds

Workers

ApplyDelayWorker (task: de_apply_delay)

Applies the computed delay (deterministic. instant in mock).

• Reads delayMs, eventId. Writes delayed, actualDelayMs

ComputeDelayWorker (task: de_compute_delay)

Computes the delay duration in milliseconds from delaySeconds.

• Parses strings to int
• Reads delaySeconds, eventId. Writes delayMs, delaySeconds

LogCompletionWorker (task: de_log_completion)

Logs the completion of the delayed event processing.

• Reads eventId, processedAt. Writes logged

ProcessEventWorker (task: de_process_event)

Processes the delayed event.

• Sets result = "success"
• Reads eventId. Writes processedAt, result

ReceiveEventWorker (task: de_receive_event)

Receives an incoming event and marks it as received.

• Reads eventId. Writes received, receivedAt

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40 tests | Workflow: delayed_event | Timeout: 60s

See RUNNING.md for setup and usage.