Pergunta de entrevista da empresa Affirm

**Writing Code Interview — 60 minutes** The exercise consisted of completing a specific method in an existing program. Some helper methods were already implemented, and the task was to use them to evaluate a set of business rules related to loans and disputes. The domain involved dispute events with different statuses, such as `Open`, `Closed`, and `Fraud`. Based on the list of dispute events associated with a loan, the method had to determine the final loan status. For example: * if at least one dispute was marked as `Fraud`, the loan should be considered fraudulent; * if all disputes were closed, the loan should be considered valid/OK; * if at least one dispute was still open, the loan should be considered under investigation. The implementation required reading an `ArrayList` of dispute events, applying the business rules, and returning the final loan status. After that, some tests were failing due to a bug in one of the already implemented helper methods. The issue was that the disputes were being sorted by ID instead of by `dateCreated`, which affected the final result. Identifying that ordering bug was the second part of the exercise. That was the full scope of the coding interview. **System Design Interview — 60 minutes** The system design interview focused on designing a data model for a peer-to-peer payment system, similar to Venmo. The use case was the following: User A wants to pay User B. Both users have an internal debit/account balance within the platform, and both may also have external bank accounts connected to their profiles. Payments involving banks had an expected delay of around two days. The main task was to design the data model needed to support this flow, including the relevant tables and attributes. The discussion then explored how the model would change depending on different payment scenarios, for example: * User A pays User B using the internal platform account; * User A pays User B from an external bank account to the platform account; * payments involving bank transfers with delayed settlement; * different combinations of internal balance and external bank accounts. The interview was focused mainly on tables, relationships, and attributes needed to represent these payment flows.