I integrate and secure payment infrastructure for platforms handling real transactions — Stripe, Razorpay, and similar gateways.

What's included: • Full gateway integration (checkout, subscriptions, or marketplace-style payouts) • Reliable webhook handling with retry logic and idempotency, so events never get lost or double-processed • Transaction reconciliation and ledger logic to keep internal records in sync with the gateway • Escrow-style state management for platforms holding funds before release (e.g. marketplaces, ticketing, bookings) • Security review of existing payment flows if you already have something built

I've shipped this exact kind of work in production — including a Stripe webhook escrow system for a multi-tenant ticketing platform and a POS-linked ledger that reconciles offline and online transactions. Full details at synkn.app/case-study.

Best fit if you need: a new payment flow built correctly from day one, or an existing integration that's dropping webhooks or has reconciliation bugs.