integrate Adyen drop-in + idempotent webhook handler in FastAPI

Category: Web Development

Budget: 1300–1300 USDC

Our CAD export platform for commercial joinery shops is expanding to the Benelux region next month. We need an engineer to replace our legacy manual invoicing flow with Adyen Drop-in UI for recurring SEPA Direct Debit and iDEAL checkout.

You will wire up the FastAPI backend endpoints, handle signature validation, and persist payment state in PostgreSQL with idempotent webhook processing and automated retries on failure. We have sandbox keys and schema specs ready in GitHub.

Skills required

• Adyen API
• FastAPI
• Python
• PostgreSQL
• Webhooks

Milestones are funded into USDC escrow on Polygon before work begins.