# Design Reliable Payment Systems

Payment teams need consistent designs for transactions, channels, reconciliation, security, and failure handling. This skill provides structured guidance, examples, and review checklists.

## Install

```bash
npx skillstore add zl2023github/payment-engineer
```

## Metadata

- Status: approved
- Slug: zl2023github-payment-engineer
- Skillstore revision: r2
- Version status: missing
- Tree hash: 0d96b056c317737223e6d0d1383f0e3f828300a8368e8baa5949d3685de6335d
- Author: zl2023github
- GitHub username: zl2023github
- License: MIT
- Repository: https://github.com/zl2023github/software-engineer-skills/tree/main/software-engineering/payment-engineer
- Ref: 88a8e9a07f4c54ab105c1c41b6267c287146b07b
- Supported tools: Claude, Codex, Claude Code
- Audit status: complete
- Agent install advisory: allowed
- Manual install advisory: allowed
- Artifact signature: available
- Audit attestation: unavailable
- Human verification: not\_verified
- Risk factors: external\_commands
- Quality score: 77
- Quality tier: bronze
- Public page: https://skillstore.pages.dev/skills/zl2023github-payment-engineer
- Manifest: https://skillstore.pages.dev/api/skills/zl2023github-payment-engineer/manifest

## Capabilities

- Structures payment platforms into access, transaction, accounting, settlement, and channel layers.
- Defines adapter interfaces for payment, query, refund, and callback operations.
- Explains idempotency, transaction state machines, and distributed consistency options.
- Provides a reconciliation workflow and an illustrative transaction matching approach.
- Lists payment risk rules, PCI-DSS controls, encryption, transport security, and log masking requirements.
- Supplies troubleshooting checklists for missing payments, duplicate charges, failed callbacks, and reconciliation differences.

## Use Cases

- Plan a payment platform: Create an architecture outline covering transaction intake, accounting, settlement, channel routing, availability, and consistency.
- Review payment reliability: Check idempotency, state transitions, callbacks, distributed transactions, and fallback behavior before implementation.
- Investigate transaction differences: Build a focused checklist for missing payments, duplicate charges, or reconciliation mismatches.

## Prompt Templates

### Outline a payment flow

```
Outline a payment flow for [payment method]. Include request validation, idempotency, channel submission, callbacks, state transitions, and customer responses.
```

### Design a channel adapter

```
Design a channel adapter for [provider] using [language]. Cover payment, query, refund, callback verification, error mapping, and retry boundaries.
```

### Plan reconciliation

```
Create a reconciliation plan for [business]. Define matching keys, time windows, fees, refunds, currencies, exception categories, and operational resolution steps.
```

### Review production resilience

```
Review this payment architecture: [architecture details]. Identify consistency, security, capacity, observability, recovery, and compliance gaps. Prioritize recommendations by financial impact.
```

## Limitations

- It provides design guidance and examples, not production-ready payment service code.
- It does not connect to payment providers or execute transactions.
- It does not replace provider documentation, legal review, PCI assessment, or security testing.
- Its channel details and thresholds require validation against current business and regional requirements.

## Best Practices

- Provide business volume, payment methods, currencies, regions, and consistency requirements.
- Validate generated designs against current provider contracts, compliance obligations, and internal security standards.
- Test idempotency, callback retries, partial failures, reconciliation exceptions, and recovery procedures before release.

## Anti Patterns

- Do not use illustrative code directly in production without validation, error handling, tests, and security review.
- Do not treat distributed locks as the only protection against duplicate financial operations.
- Do not log credentials, signatures, full card data, or unmasked personal information.

## Security Audit

- Audited at: 2026-07-23T23:49:06.004\+00:00
- Summary: All 20 static findings are false positives caused by Markdown fences, inline code formatting, or multilingual text. The skill is a documentation-only payment engineering guide with no executable commands, system reconnaissance, obfuscation, or prompt injection.

## Stats

- Views: 2
- Downloads: 6
- Favorites: 0
- Popularity score: 0