Beyond Fuzzing: How Stateful Invariants Catch Real Smart Contract Bugs

Smart contract testing with unit and fuzz tests alone misses bugs that emerge from complex sequences of interactions—the very patterns real exploits use. Invariant testing verifies that critical properties (like contract solvency) hold regardless of call order or combination, filling the security gap traditional approaches leave open. For DeFi developers, this difference between 'appears safe' and 'proven safe' represents millions of dollars in real risk.