What Happens When Two Staff Edit the Same Thing at the Same Time
The honest answer depends entirely on what's being edited. Fees101 protects some actions deliberately, because they were built around the risk of two people racing to resolve the same money. Most ordinary record edits have no such protection.
Where it's actively protected
Money-moving, approval-style actions — resolving a reconciliation entry, approving or rejecting a discount request, approving a manual payment or refund, running year-end rollover — use what's effectively a "claim": the write only succeeds if the record is still sitting in its expected starting status (usually "pending") at the exact moment it's saved.
If two staff members both try to act on the exact same pending item within moments of each other, only the first write actually lands. The second gets a plain, explicit error — something like "This payment has already been resolved by someone else, or no longer exists" on a reconciliation entry, or "This request has already been resolved" on a discount — rather than the money being applied twice or a discount being approved twice. This same pattern is what caught a real double-approval race Fees101 found and fixed in discount approvals.
Where it genuinely isn't
The practical takeaway
If you're coordinating a team editing the same student, fee item, or settings page, the safe assumption is that Fees101 will not warn you about a collision unless the action in question is one of the money-moving, approval-gated ones listed above. For anything else, avoid two people editing the same record at the same time as a matter of practice, since the app itself won't catch it for you.