Pre-Launch Diagnostic for AI-Built & Vibe-Coded Apps

If a rule only lives in your prompt, it's not a rule. It's a request.

We diagnose vibe-coded and AI-assisted applications for the silent failure modes that pass automated tests, deploy cleanly, and quietly break under real users, billing cycles, or cross-tenant traffic.

Zero Code Custody Runs locally on Cursor / Copilot. Nothing leaves your machine.
6 Empirical Checkpoints Synthesized from real production failures, not synthetic theory.
Free While In Cohort 100% free manual verification in exchange for five minutes of feedback.

Why "it deployed fine" is the most dangerous state in software

AI coding tools are designed to be agreeable. When given an ambiguous system constraint, they generate code that satisfies the prompt's English syntax without verifying the underlying database or network state.

What your AI tool verifies PASSES / GREEN
  • ✓ Syntax compiles cleanly without parse errors
  • ✓ Local dev server boots and renders mock screens
  • ✓ Single-user manual click-through works as expected
  • ✓ Git push triggers successful Vercel/Netlify build
What breaks silently in production QUIET FAILURES
  • ✕ Tenant Bleed: Supabase/Firestore rules allow any authenticated user to query another user's private data.
  • ✕ Prompt Rules: Authorization or validation logic that was told to the model in text, but never asserted in code.
  • ✕ Duplicate Submissions: Stripe or booking webhooks firing twice and creating double records.
  • ✕ Timezone Drift: Date cutoffs calculated at day granularity in UTC instead of user local time.

Audit your repo right now — zero code leaves your machine

You don't need to give us your GitHub repository. Copy our 6-checkpoint diagnostic prompt into Cursor, Claude Code, or Copilot. It scans your files locally.

quietfail_self_check_v1.prompt
You are performing an adversarial diagnostic audit on this repository. Check ONLY for the six failure patterns below, one at a time. For each checkpoint, report: (1) whether you found it, (2) the exact file and line number, (3) why it is a silent risk in plain language, and (4) the exact deterministic code fix. If nothing is found for a checkpoint, say "NOT FOUND" plainly — do not invent issues.

1. HALLUCINATED SCHEMA OR DEPENDENCIES: List every database column, table, and external package this codebase references. Cross-check against schema definitions (Prisma/SQL/migrations) and package.json. Flag anything referenced but not defined.

2. MIGRATION & SCHEMA DRIFT: Check the deployment pipeline. Does every schema modification guarantee a migration runs before new code restarts, or will running code hit unmigrated live tables?

3. RULES LIVING ONLY IN PROMPTS: Find every instruction sent to an LLM. Check whether business rules (permissions, verification, validation) described in the prompt are ALSO strictly enforced by deterministic code assertions.

4. MULTI-TENANT ACCESS & AUTHORIZATION: Find every database query and API route. Verify whether the code checks ownership (e.g. auth.uid == resource.ownerId) or if it trusts an ID supplied in the request body/params.

5. DATE & TIMEZONE BOUNDARIES: Find date comparisons (expiry, availability, subscriptions). Check if logic relies on day-level comparisons or UTC without local timezone conversion.

6. DUPLICATE-WRITE & IDEMPOTENCY: Find endpoints that record orders, payments, or bookings. Check whether concurrent submissions or retried webhooks create duplicate rows.

The 6 checkpoints grounded in real post-mortems

Every check in our procedure was derived from real incidents documented across indie SaaS builders, vibe-coders, and production failures.

CHECKPOINT 01
Ghost Columns & Silent Crashes
The Risk: Your app deploys cleanly, but crashes when real users sign up because the database is missing a column the AI assumed was already there.
Technical Root: Schema & migration drift between dev code and live production database tables.
CHECKPOINT 02
Unenforced Rules & Leaked Tiers
The Risk: You told the AI "only pro users can see this," but anyone who inspects network requests or types the direct URL can bypass the paywall.
Technical Root: Business constraints described only as English text in prompts, never asserted in backend code.
CHECKPOINT 03
Midnight & Timezone Billing Glitches
The Risk: Your app prematurely cancels active bookings, closes stores, or charges users mid-day because the server calculates dates in UTC instead of user local time.
Technical Root: Date comparisons evaluated at 24-hour day granularity without timezone offsets.
CHECKPOINT 04
Account Bleed & Cross-User Snooping
The Risk: User A logs in and can view, modify, or download User B's private orders, phone numbers, or uploaded documents simply by changing an ID.
Technical Root: Missing database Row Level Security (RLS) or trusting client-supplied user IDs without ownership verification.
CHECKPOINT 05
Double Charges & Duplicate Bookings
The Risk: A customer double-clicks "Submit" or a Stripe payment webhook retries on slow WiFi, creating duplicate records and charging their card twice.
Technical Root: Endpoints missing database unique constraints or transaction idempotency keys.
CHECKPOINT 06
Surprise 10x Overnight Hosting Bills
The Risk: A search crawler or un-isolated background loop repeatedly fires external AI API calls, quietly draining your monthly Vercel or OpenAI credits in hours.
Technical Root: Un-cached recursive loops, deprecated SDK imports, or unhandled third-party webhook storms.

What a Quietfail Audit Report looks like

No 50-page generic compliance jargon. You receive a concise 1-page action report: What was found, where it lives, the real production cost, and the exact code patch.

Report #001: Multi-Tenant Authorization Bypass
Target: Campus Logistics & Delivery Web Application
CRITICAL SEVERITY
Finding
Global database rule permits read and write access to all customer delivery records for any logged-in user. The application relies entirely on frontend UI filtering rather than backend database enforcement.
Location
firestore.rules (Lines 14–19)
Silent Risk
Any authenticated student can open browser devtools and query all customer phone numbers, room addresses, and order histories across the entire campus.
Vulnerable Code
// VULNERABLE: AI-generated rule checking only authentication, not ownership
match /orders/{orderId} {
  allow read, write: if request.auth != null;
}
Verified Fix
// VERIFIED: Enforce tenant ownership at the database boundary
match /orders/{orderId} {
  allow read, write: if request.auth != null && 
    (resource.data.customerId == request.auth.uid || request.auth.token.admin == true);
}

Three non-invasive ways to work with us

You never have to hand over proprietary code or give GitHub access to a stranger. Choose the inspection model that matches your privacy comfort.

Most Private
1. Self-Check Review
You run our prompt locally in your editor. You send us only the plain-text findings report. We review and verify the patches.
  • Zero code leaves your computer
  • 100% confidential
  • Plain-language remediation
Get Prompt
Black-Box
2. Staging URL Audit
Provide a staging URL and two test user logins. We test tenant isolation, idempotency, and boundary logic from the browser outside.
  • No repository access needed
  • Real API adversarial testing
  • Video proof of vulnerabilities
Request Staging Audit
Deep Schema
3. Schema & Route Review
Submit only your database DDL (Prisma / SQL) and API route signatures. No proprietary algorithms or business logic included.
  • Structural architecture check
  • RLS & foreign key verification
  • Webhook idempotency audit
Submit Schema

Request a free diagnostic review

All audits are currently performed by hand at no cost for Dorm2VC cohort candidates and indie builders. All we ask in return is five honest minutes of feedback.

Do NOT paste sensitive secrets, passwords, or live production API keys.

Grounded, independent, and student-founded

quietfail was founded by Abhilash Eggadi, an engineering student at NIT Warangal, incubated as part of Dorm2VC Cohort 1.

We started with a simple hypothesis: AI coding tools are extraordinary at generating functional prototypes, but structurally blind to subtle edge cases, multi-tenant boundaries, and unmigrated state. Rather than selling promises, we do every review by hand against real failure post-mortems.

Working out of: Makerspace, NGO Colony Road, Hanamkonda, Warangal, TS 506001
Direct Contact

Have a question or want to chat about failure patterns?

Email: abhilasheggadi@quietfail.me

Location Map: View Makerspace on Google Maps ↗