Payment & Billing Systems Engineer

Payment & Billing Systems Engineer

Focus: Payment processing, subscription lifecycle, financial reliability

Why this role: Studio runs on subscriptions (Free/Pro/Max) with credits, multiple payment processors, and async billing reconciliation. This is our highestrisk, least-covered system — billing bugs directly impact revenue and generate the majority of support escalations. We need a dedicated owner who has been in the trenches of real payment processing.

What you'll do:

• Own the full payment stack: Authorize.net (primary processor) and cryptocurrency payments (Solana, Ethereum, Polygon)
• Build and maintain the subscription state machine: activation, upgrades, downgrades, cancellation, past-due recovery, and suspension flows
• Design reliable webhook processing with idempotency guarantees, retry logic, and ordering safeguards
• Implement billing reconciliation workflows (hourly/daily/monthly) with audit trails and anomaly detection
• Build refund and chargeback handling workflows
• Add comprehensive test coverage for payment flows — integration tests against Authorize.net sandbox, E2E subscription lifecycle tests
• Implement fraud detection rules and rate limiting on payment endpoints 2
• Support PCI compliance requirements and payment security best practices
  

What we're looking for (non-negotiable):

• You must have direct, hands-on production experience with Authorize.net — Accept Suite, Advanced eCommerce (AIM), ARB (Automated Recurring Billing), CIM (Customer Information Manager), or Transaction Reporting APIs. This is not a nice to have. If your payment experience is limited to drop-in hosted checkout widgets, this is not the right fit
• You must have personally built a production payment system end-to-end that processed real transactions from real users — not inherited, not maintained, but architected and shipped. You understand the full lifecycle: tokenization, authorization, capture, settlement, voids, refunds, chargebacks, and reconciliation
• 3+ years building payment or billing systems in production
• Deep understanding of subscription state machines and the edge cases that break them (webhook race conditions, partial failures, duplicate events, expired cards, processor retries)
• Experience with financial reconciliation — ledger patterns, balance verification, audit logging, and discrepancy resolution
• Strong backend fundamentals in Node.js/TypeScript
• Familiarity with async job processing for billing workflows (we use Temporal)

Bonus: cryptocurrency payment integration (Solana, Ethereum, Polygon), PCI-DSS compliance experience, NestJS

Tech you'll work with: Authorize.net, Solana/Ethereum/Polygon Web3 libraries, NestJS, Temporal, PostgreSQL, Redis, TypeScript