Payment Workflow Layer

Overview

Payment Workflow Layer is the application layer that coordinates payment steps, states, decisions, retries, approvals, and downstream actions across participating services. It coordinates business progress but should not replace the ledger, settlement system, or provider-specific adapter.

Payment Workflow Layer is closely connected to Payment Execution Engine , Payment Domain Layer , and Payment State Recovery . Implementation should document components, interfaces, participants, state ownership, data stores, trust boundaries, external dependencies, failure modes, and operating responsibilities. The main risks are hidden coupling, ambiguous ownership, duplicated state, inconsistent domain models, uncontrolled boundary expansion, and recovery procedures that depend on unavailable systems. Architecture tests should include partial dependency failure, delayed events, duplicate messages, stale configuration, and disagreement between internal and external records. The operating record should preserve the original obligation, participants, amount, currency or asset, authoritative identifiers, timestamps, state history, exceptions, and final financial effect.

Payment Workflow Layer should remain distinct from Payment Execution Engine, Payment Domain Layer, and Payment State Recovery, because each can represent a different stage, record, control, or financial outcome.

Important failure modes include duplicate or delayed events, wrong destinations or currencies, stale instructions, unavailable providers, unsupported retries, and customer-facing status that differs from authoritative records. For Payment Workflow Layer, this point supports the definition’s focus on application layer that coordinates payment steps, states, decisions, retries, approvals, and downstream actions across participating services.

Contracts between layers should specify commands, events, timeouts, idempotency, error handling, and the evidence required to recover an uncertain transaction. Governance should keep diagrams, capability maps, contracts, and runbooks synchronized with the deployed system. Controls should validate inputs server-side, authenticate external events, make irreversible actions idempotent, and reconcile provider, network, settlement, and ledger evidence. For Payment Workflow Layer, this point supports the definition’s focus on application layer that coordinates payment steps, states, decisions, retries, approvals, and downstream actions across participating services.