I will build a custom API integration between your two systems

Two systems hold the same information and neither knows about the other, so someone copies it across by hand every day.

I write the layer between them. Your CRM to your spreadsheet, your store to your accounting, your form to your database, your app to a payment provider or a messaging service. Webhooks where the API offers them, polling on a schedule where it does not.

The part people skip is what happens when it fails. Mine retries with a backoff, writes what it tried and what came back, and tells you rather than silently dropping a record. A failed sync should never look like a successful one.

I have wired Microsoft Graph and Outlook into an internal task system, a print provider and a marketplace into a costing pipeline, and several language model providers behind one interface for a platform used by around a hundred people.

Tell me which two systems and what should move between them. I will check both APIs and answer with a scope before you order.