On-Premise Timer Jobs to SharePoint Online

Build an Azure WebJob to act as a scheduled job for your Office 365

Azure WebJobs SDK

https://github.com/Azure/azure-webjobs-sdk/wiki

https://docs.microsoft.com/en-us/sharepoint/dev/solution-guidance/getting-started-with-building-azure-webjobs-for-your-office365-sites

Azure WebJobs

Includes a declarative binding and trigger system that works with Azure Storage Blobs, Queues and Tables as well as Service Bus. The binding system makes it incredibly easy to write code that reads or writes Azure Storage objects. The trigger system automatically invokes a function in your code whenever any new data is received in a queue or blob. The SDK also provides an integrated Dashboard experience in the Azure management portal, with rich monitoring and diagnostics information for your WebJob runs.

Azure WebJobs SDK Samples

https://github.com/Azure/azure-webjobs-sdk-samples

GitHub Home Page

https://github.com/Azure/azure-webjobs-sdk

Check out the getting started guide, the how-to guide and the wiki. For more information on Azure and .NET see here.