FinTech platforms, B2B marketplaces, neobank layers, and usage-billed SaaS companies that need audit-grade financial accuracy frequently search to hire a freelance double-entry accounting ledger & payment reconciliation programmer. I am Aldian Fazrihady, a Senior Freelance Backend & FinTech Programmer available via Upwork.
Core Double-Entry Ledger & Financial Engineering Capabilities
- Immutable Append-Only Double-Entry Ledgers: Designing PostgreSQL ledger schemas (`journal_entries`, `postings`, `accounts`) where `SUM(debits) = SUM(credits)` is enforced transactionally and balances are never mutated via destructive `UPDATE` statements.
- Automated PSP Settlement Reconciliation: Reconciling Stripe, Adyen, Wise, Xendit, and bank payout CSV/webhook feeds against internal ledger entries to detect fee discrepancies or chargebacks automatically.
- Global Tax & E-Invoicing Integration: Integrating Stripe Tax, Avalara, TaxJar, and regional e-invoicing APIs.
Frequently Asked Questions
How do you prevent race conditions when two concurrent requests withdraw from the same wallet balance?
I use deterministic ordered `SELECT ... FOR UPDATE` account locking or serializable optimistic concurrency checks paired with idempotency keys on every ledger transaction.
How can we hire you for FinTech ledger architecture?
Contact me on Upwork or email mobile@aldianfazrihady.com.