FinTech Platform Architecture
End-to-end funds flow design, transaction risk assessment model, and KYC/AML onboarding process for a P2P digital wallet platform: nine distinct funds flow pathways, four-phase onboarding, and a real-time risk scoring layer.
Overview
This documentation covers the operational and compliance architecture for a P2P payments and digital wallet platform — drawn from compliance architecture work across three FinTech engagements. Platform-agnostic in presentation; the architecture reflects real design decisions made under live regulatory constraints.
Three interlocking components:
- Funds flow architecture — nine pathways from wallet funding through cross-border settlement
- Transaction risk assessment model — three-layer analysis producing a dynamic risk score
- KYC/AML onboarding process — four-phase sequential funnel with defined pass/fail decision points
Funds flow: nine pathways
All nine funds flow pathways route through a central wallet ledger maintained by the platform’s Banking-as-a-Service (BaaS) partner.
| Wallet Funding | ACH, card, mobile check, wire → BaaS Settlement → Platform Wallet |
| P2P Transfers | Internal ledger operations — no funds leave BaaS infrastructure; real-time debit/credit |
| Merchant Payments | User Wallet → BaaS card/ACH processing → Merchant Bank |
| Wallet Withdrawals | Push-to-card, ACH, or wire → BaaS → External Account |
| Cross-Border Transfers | USD wallet → BaaS/FX Partner → Recipient international bank or cash pickup |
| Crypto On-Ramp | USD wallet → crypto exchange integration → user crypto wallet |
| Crypto Off-Ramp | User crypto wallet → exchange → USD → Platform Wallet |
| Peer Lending | Lender Wallet → Escrow → Borrower Wallet; repayment reverse flow |
| Fee Collection | Deducted at transaction time; routed to platform fee wallet |
Transaction risk assessment
The risk model operates in three layers running in parallel on every transaction.
Data collection layer. Banking data stream: account age, average balance, transaction sizes and frequency patterns, counterparty history, chargeback history, failed transaction patterns. Crypto wallet inputs (where applicable): wallet age, transaction volume, chain analysis results, interaction with high-risk services (mixers, sanctioned addresses).
Risk analysis layer. Three parallel analytical processes: transaction frequency analysis (velocity against defined thresholds and user baseline); transaction pattern analysis (comparison to user history and peer group behavior); behavioral analysis (anomaly detection for pattern breaks, unusual timing, unexpected geography).
Risk evaluation layer. Four parallel checks — fraud risk, ML model output, terrorist financing pattern matching, illegal activity indicators — combined into a dynamic risk score mapped to Low/Medium/High.
Post-transaction processing updates the user’s risk profile, feeds results back into the model as training data, and triggers manual review for flagged transactions.
Diagram: user risk profile — three-layer model
- Account metrics: age, average balance, status
- Transaction history: sizes, frequency, counterparty
- Risk indicators: chargebacks, failed txns, suspicious activity
- Wallet analysis: age, volume, chain analysis
- Patterns: cross-chain activity, service interaction, peak times
- Risk signals: high-risk service usage, mixers, suspicious patterns
Diagram: per-transaction risk evaluation
- Velocity
- Size distribution
- Time patterns
- Wallet activities
- Chain analysis
- Service usage
- Account age
- Transaction sizes
- Counterparty history
- Recent alerts
- Behavior changes
- Rule triggers
- Amount limits
- Frequency rules
- Party verification
- Counterparty analysis
- Product usage patterns
- Transaction history
- Peer group
- Network analysis
- Behavioral patterns
- Pattern breaks
- Unusual timing
- Unexpected location
- Illegal activity signals
- Fraud indicators
- ML / TF patterns
KYC/AML onboarding: four phases
Phase 1 — Identity Verification. Customer creates digital identity; data transmits to BaaS partner via API for KYC/AML verification without touching the P2P platform. Includes: identity document verification, liveness check (biometric match), AML screening (sanctions lists, PEP lists, adverse media). Pass/fail gates before proceeding.
Phase 2 — Account Creation. Upon KYC/AML approval: platform wallet created, BaaS services provisioned, primary external bank account linked via Plaid or equivalent open banking integration.
Phase 3 — Pre-Transaction Risk Assessment. Before transaction capability is enabled: transactional fraud screening, terrorist financing screening, money laundering screening, illegal activity screening. All four must pass before the account goes live.
Phase 4 — Continuous Monitoring. Every transaction is monitored in real time against the full risk model for the life of the account. No defined end point.
Note: The platform can alternatively route KYC/AML through a dedicated third-party KYC/AML provider rather than the BaaS partner — same process, different PII storage architecture. If using a third-party provider, compliant data governance architecture for PII storage is required or the provider must handle that layer.
Diagram: high-level onboarding & risk flow
- Transactional fraud
- Terrorist financing
- Money laundering
- Illegal activities
- Transactional fraud
- Credit fraud
- Terrorist financing
- Money laundering
- Illegal activities
The KYC/AML layer can route through the BaaS partner or a dedicated third-party KYC/AML provider — the same API flow applies either way.
Diagram: detailed KYC/AML process
- Government ID
- Proof of address
- SSN
Design rationale
The four-phase sequential structure ensures that no transaction capability exists until identity, compliance, and risk checks have all passed independently. The BaaS-partner-routed KYC/AML design means the P2P platform never touches raw identity document data — it receives only a pass/fail signal. This is a deliberate architectural choice that reduces the platform’s data liability while maintaining full compliance coverage.