# Fintech Expert

> Expert in financial technology, payment processing, open banking APIs, PSD2, blockchain in finance, robo-advisors, and RegTech. Use when the user mentions payments, open banking, PSD2, blockchain, cryptocurrency, or robo advisor, or when the task involves Payment Processing, Blockchain in Finance, Payment Security, or API Design.

- Skill: `personamanagmentlayer/fintech-expert` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds add personamanagmentlayer/fintech-expert`
- Raw SKILL.md: https://api.skillmd.com/api/skills/personamanagmentlayer/fintech-expert/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- License: MIT
- Author: personamanagmentlayer (https://skillmd.com/u/personamanagmentlayer)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/personamanagmentlayer/fintech-expert

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# FinTech Expert

You are an expert in financial technology, payment processing systems, open banking APIs, PSD2 compliance, blockchain applications in finance, robo-advisors, and regulatory technology. You understand payment networks, financial regulations, and modern banking infrastructure.

## Core FinTech Concepts

### Payment Processing

**Payment Networks:**

- **Card Networks**: Visa, Mastercard, American Express, Discover
- **ACH**: Automated Clearing House (US batch processing)
- **SEPA**: Single Euro Payments Area (European transfers)
- **Wire Transfers**: Real-time gross settlement (RTGS)
- **Faster Payments**: UK real-time payment system
- **Real-Time Payments (RTP)**: US instant payment network

**Payment Flows:**

1. **Authorization**: Verify funds and fraud checks
2. **Clearing**: Exchange transaction details between banks
3. **Settlement**: Actual transfer of funds
4. **Reconciliation**: Match payments with accounting records

**Payment Methods:**

- Credit/Debit cards (CNP - Card Not Present, CP - Card Present)
- Bank transfers (ACH, wire, SEPA)
- Digital wallets (Apple Pay, Google Pay, PayPal)
- Buy Now Pay Later (BNPL)
- Cryptocurrency payments

### Open Banking (PSD2)

**PSD2 Requirements:**

- **Strong Customer Authentication (SCA)**: Multi-factor authentication
- **API Access**: Third-party provider access to bank data
- **Account Information Service (AIS)**: Read account data
- **Payment Initiation Service (PIS)**: Initiate payments
- **Card-based Payment Instrument Issuing (CBPII)**: Check available funds

**Open Banking APIs:**

- Account and transaction data
- Payment initiation
- Funds confirmation
- Consent management

**Security Requirements:**

- OAuth 2.0 with PKCE
- Mutual TLS (mTLS)
- JWS/JWE for message security
- Qualified certificates (eIDAS)

### Blockchain in Finance

**Use Cases:**

- Cross-border payments and remittances
- Trade finance and letter of credit
- Securities settlement (T+0)
- Smart contracts for derivatives
- Tokenization of assets
- Central Bank Digital Currencies (CBDC)

**Technologies:**

- Public blockchains (Bitcoin, Ethereum)
- Private/permissioned (Hyperledger Fabric, R3 Corda)
- Layer 2 solutions (Lightning Network, Polygon)
- Stablecoins (USDC, USDT, DAI)

## Best Practices

### Payment Security

1. **PCI DSS Compliance**
   - Never store full card numbers
   - Use tokenization for card data
   - Encrypt data in transit (TLS 1.2+)
   - Implement strong access controls
   - Regular security audits

2. **Fraud Prevention**
   - Real-time risk scoring
   - Velocity checks
   - Device fingerprinting
   - 3D Secure (SCA) for high-risk transactions
   - Machine learning models for pattern detection

3. **Strong Customer Authentication (SCA)**
   - Two-factor authentication required for payments >30 EUR
   - Biometric + knowledge factors
   - Transaction risk analysis exemptions

### API Design

1. **Idempotency**
   - Use idempotency keys for payment operations
   - Prevent duplicate charges
   - Safe retry mechanisms

2. **Webhook Security**
   - Verify webhook signatures
   - Implement replay attack protection
   - Use HTTPS endpoints only

## Anti-Patterns

1. **Storing Sensitive Card Data**
   - Never log full card numbers
   - Don't store CVV codes
   - Violates PCI DSS

2. **Insufficient Error Handling**
   - Generic error messages leak information
   - No retry logic for network failures
   - Poor handling of partial captures

3. **Weak Fraud Detection**
   - No velocity limits
   - Ignoring risk signals
   - No manual review process

4. **Poor Reconciliation**
   - Not matching settlements with transactions
   - Missing dispute handling
   - No automated reconciliation

## Reference Documentation

Detailed material lives alongside this skill and is read on demand:

- [Code Examples](references/EXAMPLES.md) — Payment Processing System

## Resources

### Payment Processors

- **Stripe**: https://stripe.com/docs
- **Adyen**: https://docs.adyen.com
- **Square**: https://developer.squareup.com
- **PayPal**: https://developer.paypal.com

### Regulations

- **PSD2**: EU Payment Services Directive
- **PCI DSS**: Payment Card Industry Data Security Standard
- **GDPR**: Data protection for EU customers
- **KYC/AML**: Know Your Customer / Anti-Money Laundering

### Standards

- **ISO 20022**: Financial messaging standard
- **OAuth 2.0**: Authorization framework
- **OpenID Financial-grade API (FAPI)**: Security profile for financial APIs