When a record-triggered flow performs an action that causes a trigger to fire, which order of execution phase is this?
Record-triggered flows configured to run before or after save operate within the exact same database transaction as the DML operation that initiated them. When such a flow performs an action that subsequently causes an Apex trigger or another automation to fire, that secondary trigger satisfies the stem's condition by executing immediately within that very same transactional context, rather than being deferred or routed asynchronously.
Why this answer
This is part of the re-entrant execution, where Salesforce processes the trigger as part of the flow's transaction.