Smart contract security isn’t optional. Once deployed, bugs can’t be patched easily, and exploits can drain funds or break trust permanently.

At NsisongLabs, we’ve audited contracts handling millions in value. Here’s what we look for and how to prepare.

1. Common Vulnerability Categories

Most smart contract issues fall into a few patterns:

Reentrancy attacks: Functions that call external contracts before updating state can be exploited to drain funds or manipulate logic.

Access control flaws: Missing or incorrect permission checks allow unauthorized users to execute critical functions.

Integer overflow/underflow: Arithmetic operations that don’t handle edge cases can produce unexpected results.

Front-running: Transaction ordering vulnerabilities where attackers can see pending transactions and submit higher-fee transactions to execute first.

Logic errors: Business rules that don’t match intended behavior, especially around edge cases and boundary conditions.

2. Preparing for an Audit

Before engaging auditors, ensure:

• Complete test coverage: Unit tests, integration tests, and fuzz tests covering happy paths and edge cases.
• Documentation: Clear comments explaining business logic, especially for complex calculations.
• Formal verification: For critical contracts, consider formal verification tools to prove mathematical properties.
• Gas optimization review: While not security, inefficient code can make attacks more expensive to execute.

3. What Auditors Examine

A thorough audit covers:

Code review: Line-by-line analysis of contract logic, looking for vulnerabilities and design flaws.

Architecture review: How contracts interact with each other, external dependencies, and upgrade mechanisms.

Economic analysis: Tokenomics, incentive structures, and potential attack vectors from economic manipulation.

Integration testing: How contracts behave with real-world inputs and in combination with other protocols.

Compliance review: Whether contracts meet regulatory requirements for your jurisdiction.

4. Post-Audit Remediation

After receiving audit findings:

• Prioritize by severity: Critical issues must be fixed before deployment; medium issues should be addressed; low issues can be documented.
• Re-test everything: Fixes can introduce new bugs—re-run full test suites.
• Consider re-audit: For critical fixes, a focused re-audit of changed code is often worth it.

Smart contract security is a continuous process. At NsisongLabs, we’ve seen projects that skip audits pay the price later. Regular audits, especially before major upgrades or when adding new features, help maintain trust and protect users. Whether you’re building DeFi protocols, NFT marketplaces, or enterprise blockchain solutions, investing in security audits upfront saves time, money, and reputation down the line.