Fintech Infrastructure Prototype

Understanding
how money actually moves.

Payment Bridge Core is a backend-first fintech infrastructure prototype that models the systems behind digital payments — from authentication and wallets to settlement, reconciliation and multi-rail orchestration.

Java 21Spring BootJWTLedgerSettlementReconciliation
9
Core Modules
3
Payment Rails
Ledger
Source of Truth
Double
Entry Accounting

Payment Bridge Core

End to end flow

live flow
Payment Bridge Core
End to end flow
User
Login / Register
Auth (JWT)
Session validated
Wallet
Balance from Ledger
Payment
Idempotency key
KYC / Balance / FX / AML
Pre-payment processing
Settlement
Hold / complete / release
Ledger
Double Entry
Payment Completed
PDNG → ACCP → STLD
MockRail
sandbox
StripeRail
sandbox
CbdcRail
sandbox

Architecture snapshot

Built like a bridge, not a dashboard.

Payment Bridge Core models how money moves through authentication, wallets, ledger, settlement and external payment rails. The architecture focuses on correctness, traceability and keeping financial logic independent from individual payment channels.

Implemented

JWT authWalletLedgerFXKYC / AMLSettlementReconciliation

Designed for

Multi-rail routingCBDC sandboxDouble-entry postingIdempotencyPartner bridge

Project vibe

Backend-firstMinimalFintechReadableEngineering showcase

Core principles

Ledger-first balances

Balance comes from entries, not a floating stored value.

Rail abstraction

Mock, Stripe, and CBDC all pass through the same core flow.

Settlement

Hold, completion, and release stay balanced in the ledger.

Reconciliation

The system checks that local and remote state still agree.