Building a booking system with FastAPI? Let us review it.
Expert code review for booking systems built with FastAPI. We fix FastAPI-specific security gaps, optimize performance, and handle deployment. From $19.
Common FastAPI issues we find
Real problems from FastAPI codebases we've reviewed.
Blocking calls inside async endpoints
Synchronous database calls, file operations, or HTTP requests inside async def endpoints block the entire event loop, making your API unresponsive under load.
Missing authentication on endpoints
API routes that handle sensitive data or actions without any auth middleware — Depends() for authentication is simply not included in the route definition.
No CORS configuration
CORSMiddleware either missing (blocking all cross-origin requests) or set to allow_origins=['*'] (allowing any website to call your API).
Pydantic models without validation constraints
Request models that accept any string length, any number range, and any format. No Field() constraints, so invalid data flows through your system.
Booking System challenges to solve
Key booking system concerns that AI-generated code often misses.
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.
What we check
Key areas we review for FastAPI booking system projects.
Double-booking prevention — atomic availability checks and booking creation
Timezone handling — correct display and storage across all timezones
Payment integration — deposits, refunds, cancellation policy enforcement
Notification pipeline — confirmations, reminders, cancellation alerts
Not sure if your app passes? Our code audit ($19) checks all of these and more.
Start with a self-serve audit
Get a professional review of your FastAPI booking system project 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.
How it works
Tell us about your app
Share your project details and what you need help with.
Expert + AI audit
A human expert assisted by AI reviews your code within 24 hours.
Launch with confidence
We fix what needs fixing and stick around to help.
Frequently asked questions
Can you review a booking system built with FastAPI?
Yes. We regularly audit FastAPI booking system projects and understand the specific patterns and pitfalls of this combination. Our review covers security, performance, and deployment readiness.
What issues do you find in FastAPI booking systems?
Common issues include blocking calls inside async endpoints and missing authentication on endpoints on the FastAPI side, combined with booking system-specific concerns like double-booking prevention and timezone handling. We check for all of these and more.
How do I make my FastAPI booking system production-ready?
Start with our code audit ($19) to get a prioritized list of issues. For FastAPI booking system projects, the typical path is: fix security gaps, address booking system-specific requirements, optimize FastAPI performance, then configure deployment. We provide a fixed quote after the audit.
How long does it take to audit a FastAPI booking system?
Our code audit delivers a full report within 24 hours. For FastAPI booking system projects, we check security, architecture, performance, and deployment readiness across all FastAPI-specific patterns. Fixes are scoped separately with a fixed quote.
Related resources
FastAPI by Use Case
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