"wallet"

0 articles

Prisma Optimistic Locking in Practice: Dual-Currency Wallet System with Audit Trail for Financial Tracking

An in-depth analysis of a production-grade NestJS wallet service, covering Prisma update where optimistic locking, dual-currency accounting (cash + coins), freeze/unfreeze mechanisms, and complete transaction flow tracking.

Backend Development

Deep Dive into Payment Webhook & Callback Handling — Optimistic Locking, Idempotency, Atomic Wallet Operations

In-depth analysis of PaymentWebhookController (single endpoint routing + callback-token authentication) → handleUniversalWebhook (deposit/withdrawal routing) → handleInvoiceWebhook (updateMany optimistic locking + creditCash) → handlePayoutWebhook (atomic unfreeze + CRITICAL degradation) → WalletService (ensureWallet / creditCash / freezeCash / unfreezeCash + beforeBalance/afterBalance audit trail)

Management Backend

Full Payment Process Chain — API Xendit → Flutter App → admin-next Financial Audit

NestJS PaymentService (Xendit Invoice/Payout Gateway) → ClientWalletService (Deposit/Withdrawal/Webhook Callback Business Logic) → admin-next Finance Page (WithdrawalList, DepositList, TransactionList)

Management Backend

admin-next Order Management System — 9 Status Transitions + Refund Approval + Permission Control

In-depth analysis of the admin-next order management system: Order model with 32 fields, 9 status enums and transition restrictions, useAntdTable pagination and search, refund approval transaction (wallet deduction + coin refund), unit test coverage, covering the complete frontend and backend chain.

Management Backend