I write property-based fuzz test suites using Foundry invariant testing and Echidna that systematically find the edge cases your unit tests miss — the inputs no developer thinks to manually specify.
Invariant categories I cover: AMM price invariant preservation (constant product, constant sum); vault accounting correctness (share/asset ratio at all states); access control invariants (state changes only happen via authorised callers); balance conservation (no funds created or destroyed); protocol solvency under adversarial deposit/withdrawal sequences; and custom business logic invariants specific to your protocol.
For stateful testing I write handler contracts that simulate realistic multi-step user interactions (deposit, borrow, repay, liquidate, withdraw) so the fuzzer can explore complex state transitions, not just individual function calls.
Deliverables: fuzz test suite integrated into your project, test documentation explaining each invariant and its security rationale, a campaign findings report, and optional CI pipeline integration so tests run on every PR.
Share your repository and a high-level description of what your protocol should never allow — I'll translate that into concrete invariants and implement them.