Back at my previous full-time position I was responsible for implementing a custom data integration between our eCommerce system (Magento 2) and ERP system (SAP byDesign)
The project required extensive API testing (REST & SOAP) and managing a service in between the systems responsible for health monitoring and issue tracing.
Part of the integration was running in real-time by reacting to specific actions in our systems using webhooks and the rest has run on a predefined schedule with CRON jobs.