For Vogsy I developed several intergrations in CRMs (Hubspot, Salesforce & Copper) and financial applications (Quickbooks, Exact & Xero). I also provided a base for a Zapier application that lets users automate things together with Vogsy.
All API integrations where build with Python on App Engine. For each integration a seperate integration layer is build with full test-coverage. The architecture is based on Domain Driven Design (DDD).