We can develop remote event receiver in SharePoint online using visual studio 2015. In SharePoint online Office 365 environments we can not run custom code in the SharePoint server. But we can run code in a remote server. Remote event receivers can be developed using provder hosted add-in. We can use remote event receivers to handle events in the SharePoint add-in model. We can use AppInstalled and AppUninstalling events to set up or remove SharePoint objects and other event receivers your add-in needs.