A NestJS app to experiment with Domain Driven Design, beyond the usual "Todo App" scenario
To try and improve my understanding of Domain Driven Design in a more real-world style example, this repository builds an imaginary "expense management platform" for submitting expense claims, reviewing them, approving them, or escalating them.
- An Expense Claim consists of one or more Expense Line Items.
- Each Expense Line Item includes details like a description, amount, currency, and potentially an expense category or type.
- Expense Approvers review submitted Expense Claims. For each Expense Line Item, they will decide to either Approve it or Escalate it for further review.
- The review process is all-or-nothing: Expense Approvers must make a decision for every Expense Line Item on the Expense Claim before they can Submit the Approval. There's no partial submission or draft state for this stage.
- Once an Expense Claim review is submitted, the system automatically creates an Escalated Line Item task for each Expense Line Item that was marked for escalation. If all items are approved, no such tasks are created.
- A secondary group of users, such as Finance Reviewers, will then review these Escalated Line Items and make a final decision on them.
- All users involved (Expense Approvers and Finance Reviewers) can add notes. These notes can be at the overall Expense Claim level, or specific to an Expense Line Item when it's being Escalated (this would be an Escalation Reason).