Fintech & Payment Rails

The vision

Global fintech authority starts with rails you can prove: multi-vendor PSP orchestration, multi-currency books that agree with PSPs, and settlement narratives regulators and investors can follow without hero spreadsheets.

The challenge

Teams stitch Paystack, Paga, Stripe, and card acquirers without a unified idempotency and ledger story—FX drift, duplicate webhooks, and NGN/USD/EUR splits that never reconcile under audit pressure.

How Aristos delivers

We engineer payment cores with explicit state machines, webhook signing with replay windows, and immutable event-sourced ledgers. First-class adapters for Paystack, Paga, Stripe Connect–class splits, and Open Banking—so treasury sees one truth while product ships fast.

Engineering checklist we hold ourselves to—not a generic SLA slide.

• Idempotency keys and deduplication on every money-moving endpoint
• PCI-scoped tokenization patterns; no PANs in application logs
• Webhook signature verification with clock-skew tolerance and replay windows
• Settlement reports exportable for finance with immutable event sourcing

Elite tools we deploy by default for this practice area.

• Node.js / Go workers · PostgreSQL with row-level security for tenant wallets
• Stripe Connect–class patterns where applicable · Open Banking adapters
• Temporal or BullMQ for payout orchestration with compensating transactions

Engineering depth

• Sandbox simulators for PSP failure modes before production traffic
• FX rate sourcing with staleness alerts and hedge-friendly audit fields
• Chargeback and dispute hooks modeled as first-class domain events