Payment Integration & Migration
Mission-critical payment systems, built and migrated without drama
Billing is the one system where a bad deploy costs real money in real time. I design and run payment integrations and migrations the way they have to be done: idempotent, reconciled, reversible. The largest one — moving hundreds of millions in recurring revenue from Adyen to Stripe for Babbel — finished with zero downtime.
Gateway integration
- Stripe, Adyen, PayPal, Braintree, NMI — implemented against your actual flows, not the quickstart
- Cards, Apple Pay, Google Pay, ACH, SEPA, and local methods per market
- Subscription billing, usage-based pricing, trials, and lifetime tiers
- Radar fraud tuning, PCI-conscious architecture, webhook handling that survives retries
Zero-downtime migration
- Card vault re-tokenization and mandate rebuilding across providers
- Customers keep their auth, billing day, and payment method — they never notice
- Verification and reconciliation pipelines with full audit trails
- Rollback strategy and staged cutover, so risk is bounded at every step
Hardening what you have
- Payment retry logic and dunning management that wins back failed charges
- Event-driven reconciliation on AWS (EventBridge, SQS, Lambda) with automatic retries
- Idempotent background jobs for billing operations at scale
- Multi-currency, tax, and localization edge cases handled before they page you
Stack & tools
- Stripe
- Adyen
- PayPal
- SEPA
- Ruby on Rails
- Node.js
- AWS
- Terraform
Proof
Where this has worked before
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Need payment work done without drama?
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