Appointment Booking System
Seamless scheduling platform for service-based businesses
A sophisticated appointment booking platform that enables customers to browse available time slots, reserve services, receive automated reminders, and process online payments. Includes provider schedule management, resource allocation, and comprehensive notification workflows.
Business Problem
Service providers were losing revenue due to no-show appointments, double-booking errors, and the administrative overhead of manual scheduling. Customers expected 24/7 online booking capability with instant confirmation.
Solution
Built a booking system with real-time availability calendars, conflict detection engine, automated email and SMS reminder workflows, and integrated payment processing. Uses database-level locks for slot reservation to prevent double-booking and a queue-based notification dispatcher.
Architecture
Domain-driven design with Booking Engine, Availability Service, Payment Gateway, Notification Dispatcher, and Calendar Integration modules. Uses pessimistic locking for slot reservations, queued notifications with retry logic, and a timezone-aware scheduling system.
Challenges
Preventing race conditions in slot reservation under high concurrency, supporting multiple timezones across global providers, implementing reschedule logic that handles payment refunds, and building a flexible recurrence rule engine for recurring appointments.
Performance Optimizations
Redis-based slot caching reduced calendar load time by 90%, batch notification processing improved email delivery throughput by 5x, optimized database indexes eliminated full-table scans on availability queries, and implemented Slack notifications for critical booking failures.