Who Should Audit Your AI-Built App? Scanners, Vibe-Audit Firms, Pentesters or a Fractional CTO
Four very different things get called an audit. Scanners find known patterns, pentesters attack a running app, fixed-price vibe-audit services review a snapshot, and a fractional CTO fixes the architecture underneath. Here is what each one covers, what it hands you, and when each is the right pick.
Short answer: run a scanner today because it is free, get a penetration test when a customer or regulator asks for one, use a fixed-price vibe-audit service when you want a quick second opinion on a small app, and hire a fractional CTO audit when the app is your business and you need it fixed, not just graded. Most founders asking this question need the first and the last.
The four options are not competitors. They answer different questions, and the mistake I see most is buying one expecting the answers of another: a pentest report with forty findings and no idea which three matter, or a scanner score of 92 on an app where any user can read any other user's data.
The four options, side by side
| Automated scanners | Semgrep, Snyk, OWASP ZAP, SonarQube, GitHub's built-in scanning. Scope: known patterns: leaked key formats, vulnerable dependencies, raw query construction, common misconfigurations. Deliverable: a list of findings with severities, continuously. Turnaround: minutes. Price shape: free tiers that cover most small apps, then per-seat or per-repo plans. Blind spot: anything about what your product is supposed to allow. |
|---|---|
| Fixed-price vibe-audit services | Productized reviews aimed at Lovable, Bolt, Cursor and Replit builders. Scope: a checklist review of a snapshot of the code and the hosted app, often with a scan behind it. Deliverable: a report, sometimes a call. Turnaround: days. Price shape: a published fixed fee. Blind spot: the fix. You get the list and do the work yourself, and the reviewer rarely runs the system or restores your backups. |
| Penetration testers | Specialist security firms, from boutiques to Cobalt and Bishop Fox. Scope: attacking a running application the way an adversary would, against a defined target and time box. Deliverable: a formal report with reproducible findings, suitable for customers, insurers and auditors. Turnaround: one to several weeks, booked ahead. Price shape: quoted per engagement, scaled by scope. Blind spot: reliability, maintainability, backups, scaling, and whether the thing should be built this way at all. A pentest confirms doors are locked; it does not tell you the building is on sand. |
| Fractional CTO audit | What I do: the AI-built app audit. Scope: security plus reliability, data handling, maintainability and growth, by reading the code and testing the running system, including the boring parts like restoring a backup. Deliverable: a system map, each finding with evidence and a verdict, and a prioritized plan, then hands-on fixes with your team or your AI tools. Turnaround: a 30-day discovery, then hardening. Price shape: a fixed-scope discovery quoted on a call, after a free five-minute self-check. Blind spot: it is not a formal pentest report, and it is overkill for a weekend project. |
When each one is the right pick
Pick a scanner when
Always. It costs nothing and takes an hour. Turn on secret scanning and dependency alerts in your repository today, regardless of what else you buy. Just know that a clean scan says nothing about authorization, environments, monitoring or backups, which is where AI-built apps actually fail. The ten checks show which is which.
Pick a fixed-price vibe-audit service when
The app is small, pre-revenue or a side project, you can do the fixes yourself, and you want a structured second opinion for a known price. It is a sensible middle step. Ask two questions before paying: will a person run the app and test it with two accounts, and will they tell you what to fix first rather than everything at once. If the answer to either is no, you are buying a scan with a cover page.
Pick a penetration test when
Someone else requires the report: an enterprise customer's security questionnaire, a cyber-insurance application, a compliance program, or a partner integration. Get one after you have fixed the obvious gaps, not before, or you pay a specialist to rediscover a key in your bundle. When an audit I run shows that a formal pentest is needed, I bring in my security practice, geearr.com, which does those.
Pick a fractional CTO audit when
The app is the business. Customers depend on it, an investor or partner is looking at it, the person who built it is you or a contractor who has moved on, and the question you actually have is "can I build on this or do I start over". That question is architectural, not just security, and the answer in my experience is almost always "build on it", once a short list of gaps is closed. You want someone who will find the gaps, show you the evidence, order them, and then fix them alongside you without stopping feature work.
When it isn't me
If you need a formal pentest report by itself, go to a pentest firm. If you are a solo builder on a weekend project with no customers, run the scanners and take the free check; you do not need a 30-day discovery. If what you want is a team to take over the product entirely, you want an agency, not an audit.
Three comparisons people actually ask
Code audit vs. penetration test
A code audit reads the code and configuration and asks whether the system is built right. A penetration test attacks the running system and asks whether it can be broken into. They overlap on security and diverge everywhere else. If you can only afford one and nobody is demanding a report, the audit finds more of what will hurt you; if a customer is demanding a report, only the pentest satisfies them.
Fractional CTO vs. a software agency for fixing an AI-built app
An agency sells hours and is paid to build. The honest ones will still tell you to keep what works, but the incentive points toward a rebuild in their stack. A fractional CTO is paid to decide, and to leave you with a system your own team or your own AI tools can maintain. If you want to hand the product over entirely, an agency fits. If you want to keep ownership and get it to production grade, the audit fits.
Technical due diligence firm vs. fractional CTO
A due diligence firm works for the investor and produces a risk assessment for a deal. A fractional CTO works for you and produces the fixes and the evidence that make that assessment go well. If you are preparing for a raise, read what investors check in AI-generated codebases; the same 30-day discovery that hardens the app also produces the evidence pack.
How to decide in one minute
- No customers yet: scanners plus the free check. Stop there.
- Customers, and you can do the fixes: scanners, then a fixed-price review or the free check plus the ten checks.
- Customers, partners or investors depending on it, and you want it fixed: the audit, starting with the discovery.
- Someone is asking for a formal report: fix first, then a pentest.
The free Vibe Reality Check takes five minutes and tells you which of the four you need. If you already know, book a 30-minute call.