The Work-In-Progress (WIP) pattern is a design approach used in software development that enables gathering chunks of data over time, allowing for review and submission to the server for processing. The key component of this pattern is a persistent "work document" that is enriched with input over time before being submitted for processing. A WIP application should support operations such as creating, reading, listing, filtering, updating, canceling, and submitting documents. This approach can be implemented using Azure Durable Functions, which allows modeling workflows as sets of functions interacting with each other, providing built-in instance management APIs to fulfill the requirements of a WIP system. The WIP pattern is useful in scenarios requiring data collection from multiple sources and submission for processing, such as onboarding employees, where it can handle data entry, manual approvals, and review processes.