August 8, 2026 · 12 min read · RelayLink Engineering
Once a smart contract is deployed, the code is effectively permanent. There is no patch window and no rollback unless you designed for it. That asymmetry is why security review belongs in the development process, not at the end of it.
For every state-changing function, ask who is allowed to call it and what happens if they call it maliciously. Missing or overly broad modifiers are among the most common causes of serious losses. Prefer explicit roles over a single owner, and make privileged operations visible in events.
Any call to another contract hands control to code you do not own. Follow checks-effects-interactions, use reentrancy guards where appropriate, and never assume an external call returns in the state you left it.
Solidity 0.8+ protects against overflow, but rounding, division order and decimal assumptions still cause real bugs. Define the precision of every value, document the rounding direction, and test boundary amounts.
If the contract is upgradeable, the storage layout is part of the security surface. Changing variable order or types across upgrades can corrupt state. Use audited proxy patterns, timelocks and multi-signature approval for upgrades — and rehearse the upgrade before executing it.
Any price, timestamp or identifier that comes from outside the chain can be manipulated. Use established oracle designs, validate ranges, and design the failure mode for stale or missing data.
No team should be the final reviewer of its own critical code. An independent audit combines static analysis, adversarial testing and a manual review of business logic. The output should be a written report with severity ratings and reproducible findings — and remediation should be re-tested, not assumed.
Building something on-chain? RelayLink performs independent smart contract audits and delivers contracts built to pass them. Talk to our security team.