Server-side save validation
Cloud saves now pass through a server-side validation layer before they're written to the database. Every insert and every update runs through a PostgreSQL trigger that checks your character data against the game's rules. If something doesn't add up, the save is rejected.
The checks are intentionally generous — we're not auditing rounding errors. But if your level 12 character has 900 stat points, or you gained 15 levels between two saves that were 10 seconds apart, or your boss kill count went backwards, the save doesn't go through. Scrap income is rate-limited so you can't script rapid small deposits. Your class can't change mid-save. Enhancement levels can't exceed the system cap.
Delta validation compares each incoming save against the previous one. Absolute bounds catch the obvious stuff — stats outside the possible range, negative values, invalid class IDs. Delta checks catch the subtle stuff — incremental manipulation that stays within absolute limits but moves too fast to be legitimate play.
If you're playing normally, you'll never notice this exists. That's the point.