Should you use automated scanning tools or hire human auditors? The answer is both, but knowing when to prioritize each approach could save you six figures. Automated tools catch 30-40% of vulnerabilities in seconds. Human experts find the remaining 60-70% — the business logic bugs, economic attacks, and edge cases that no tool can detect.
Automated Analysis: The Fast First Pass
What It Catches
- Known vulnerability patterns (reentrancy, overflow, missing checks)
- Code quality issues (unused variables, shadowing)
- Standard compliance deviations
- Gas optimization opportunities
What It Misses
- Business logic flaws ("does this code do what the protocol intends?")
- Economic attack vectors (flash loan strategies, oracle manipulation)
- Cross-contract interaction bugs
- Protocol-specific edge cases
- Novel attack patterns not yet in databases
Manual Review: The Deep Dive
What It Catches
- Everything automated tools find, plus:
- Business logic vulnerabilities
- Economic model weaknesses
- Novel attack vectors
- Context-dependent bugs that require understanding protocol intent
What It Costs
2-12 weeks, $20K-$500K. Human experts are expensive and slow. But for critical protocols handling millions in TVL, there's no substitute.
When to Use Each
| Scenario | Recommended | Why |
|---|---|---|
| Early development | Automated only | Catch basic issues fast during iteration |
| Pre-launch (<$1M TVL) | Automated + light manual | Good coverage at reasonable cost |
| Pre-launch ($1M+ TVL) | Full manual + automated | Stakes justify thorough review |
| Post-upgrade | Automated + focused manual | Review changes specifically |
| Ongoing monitoring | Automated continuous | Catch regressions immediately |
The Vultbase Approach: Challenge-Based Testing
We combine the speed of automated analysis (Slither, Semgrep, 1,200+ patterns) with engineer validation. Every automated finding is reviewed by a human expert who understands DeFi. Every challenge result is contextualized against your specific protocol.
Get the best of both worlds. Start with an automated scan ($499) and upgrade to engineer-validated testing as you scale.