Built a booking system with GPT Engineer?
We'll make it production-ready.
Booking systems coordinate scarce resources — time slots, rooms, tables, appointments — between providers and customers. A double-booking or a missed confirmation email directly costs you money and trust. AI tools build attractive calendar UIs quickly, but the underlying scheduling logic, timezone handling, and payment integration need to be bulletproof before you take real bookings.
Booking System challenges in GPT Engineer apps
Building a booking system with GPT Engineer is a great start — but these challenges need attention before launch.
Double-booking prevention
Two customers booking the same time slot simultaneously is the most critical failure mode. AI-generated booking logic often has race conditions — checking availability and creating the booking aren't atomic, so two requests can both see the slot as available and both succeed.
Timezone handling
If your provider is in New York and your customer is in Los Angeles, a '2 PM appointment' means different things. AI tools store times in the server's timezone or the developer's local timezone, causing bookings to appear at wrong times for users in other timezones.
Calendar integration and availability
Providers have existing calendars (Google Calendar, Outlook) that affect their availability. Without two-way calendar sync, providers get double-booked with their personal events, or manual availability management becomes a full-time job.
Payment and cancellation policies
Bookings often require deposits or full prepayment. Cancellation policies (full refund within 24 hours, 50% after that, no refund day-of) need precise time-based logic. AI tools implement basic checkout but not the nuanced refund rules that booking businesses need.
Confirmation and reminder notifications
No-shows kill booking businesses. You need immediate booking confirmations, reminders at 24 hours and 1 hour before, cancellation notifications, and rescheduling flows. AI tools send a confirmation email at best — the full notification pipeline is usually missing.
Recurring bookings and scheduling rules
Weekly appointments, buffer time between bookings, lunch breaks, holidays, and maximum bookings per day are all scheduling rules that AI tools don't implement. Without these constraints, your calendar becomes unmanageable for providers.
Waitlist and cancellation backfill
When a popular time slot opens up due to cancellation, you need to notify waitlisted customers automatically. This turns lost revenue into recovered bookings. AI tools don't build waitlist functionality.
What we check in your GPT Engineer booking system
Common GPT Engineer issues we fix
Beyond booking system-specific issues, these are GPT Engineer patterns we commonly fix.
No authentication system
GPT Engineer generates functional UIs but typically skips authentication entirely. All routes and data are publicly accessible.
Direct database access from client
Some generated apps query databases directly from the frontend without an API layer, exposing database credentials and structure.
Incomplete feature implementations
Features that look complete in the UI but don't actually work end-to-end. Buttons that don't submit, forms that don't save, and links that go nowhere.
Missing error boundaries
A single component error crashes the entire application. No error boundaries or fallback UIs to gracefully handle failures.
Start with a self-serve audit
Get a professional review of your GPT Engineer booking system at a fixed price.
External Security Scan
Black-box review of your public-facing app. No code access needed.
- OWASP Top 10 vulnerability check
- SSL/TLS configuration analysis
- Security header assessment
- Expert review within 24h
Code Audit
In-depth review of your source code for security, quality, and best practices.
- Security vulnerability analysis
- Code quality review
- Dependency audit
- Architecture review
- Expert + AI code analysis
Complete Bundle
Both scans in one package with cross-referenced findings.
- Everything in both products
- Cross-referenced findings
- Unified action plan
100% credited toward any paid service. Start with an audit, then let us fix what we find.
Frequently asked questions
Can I build a booking system with GPT Engineer?
GPT Engineer is a great starting point for a booking system. It handles the initial scaffolding well, but booking systems have specific requirements — double-booking prevention and timezone handling — that need professional attention before launch.
What issues does GPT Engineer leave in booking systems?
Common issues include: no authentication system, direct database access from client, incomplete feature implementations. For a booking system specifically, these issues are compounded by the need for double-booking prevention.
How do I make my GPT Engineer booking system production-ready?
Start with our code audit ($19) to get a clear picture of what needs fixing. For most GPT Engineer-built booking systems, the critical path is: security review, then fixing core flow reliability, then deployment. We provide a fixed quote after the audit.
How much does it cost to fix a GPT Engineer-built booking system?
Our code audit is $19 and gives you a complete report of issues. Fixes start at $199 with our Fix & Ship plan. For larger booking system projects, we provide a custom fixed quote after the audit — no hourly billing.
Get your GPT Engineer booking system production-ready
Tell us about your project. We'll respond within 24 hours with a clear plan and fixed quote.