Design a backend state machine for a business workflow such as an order, application, claim, or approval process.

Design a business workflow state machine

Designs explicit workflow states, allowed transitions, guard rules, audit history, idempotency, and operational repair paths.

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I would model the workflow with explicit states and allowed transitions. Each transition has a command, actor, guard rules, timestamp, and optional reason. The API exposes operations such as submit, approve, reject, cancel, or reopen rather than letting clients set arbitrary status values. The database stores the current state and a transition history so the system can explain how it got there.

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State modeling, transition guards, idempotency, concurrency, audit history, side effects, retries, and repair operations.

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Why this question matters
Many backend products are state machines hidden behind status fields. Explicit states, guarded transitions, concurrency rules, history, and repair paths keep business behavior from scattering across controllers and jobs.
I would model the workflow with explicit states and allowed transitions. Each transition has a command, actor, guard rules, timestamp, and optional reason. The API exposes operations such as submit, approve, reject, cancel, or reopen rather than letting clients set arbitrary status values. The database stores the current state and a transition history so the system can explain how it got there.
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I would handle concurrency and side effects carefully. Optimistic concurrency prevents two reviewers from making conflicting transitions. Side effects such as notifications, billing updates, or queue messages can be triggered after a successful transition using an outbox or reliable event pattern. Idempotency keys help retries of the same command return the same result without applying the transition twice.

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Letting clients submit arbitrary status values.
Spreading transition rules across controllers and workers.
No history of how the workflow reached its current state.
Triggering side effects before the state transition commits.

Design a backend state machine for a business workflow such as an order, application, claim, or approval process.

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