Telehealth platforms, coaching/tutoring marketplaces, field-service dispatchers, and AI recruiting tools frequently search to hire a freelance Google Calendar API, Microsoft Graph Outlook Calendar, Cal.com, Nylas, or Cronofy scheduling programmer. I am Aldian Fazrihady, a Senior Freelance Full Stack Developer available via Upwork.
Core Multi-Timezone Scheduling & Calendar Sync Capabilities
- Real-Time Two-Way Calendar Synchronization: Handling Google Calendar push notifications (`events.watch`), Microsoft Graph delta tokens, recurring `RRULE` (RFC 5545) expansion, and exception dates (`EXDATE`) without phantom duplicate events.
- Round-Robin & Collective Availability Engines: Computing sub-50ms free/busy slot intersections across multiple team members, buffer times, daily booking caps, and IANA time zones (`America/New_York`, `Europe/London`, `Asia/Jakarta`).
- AI Scheduling Assistants (Voice, SMS, WhatsApp & Email): Allowing end users to book, reschedule, or cancel appointments conversationally with automatic Zoom/Google Meet link provisioning.
Frequently Asked Questions
How do you prevent Daylight Saving Time (DST) bugs in recurring appointment systems?
I store all UTC instants alongside the provider's explicit IANA timezone identifier (never static UTC offsets like `-05:00`) and expand `RRULE` recurrences in local wall-clock time before converting to UTC.
How can we hire you as a freelance calendar & booking engine programmer?
Contact me on Upwork.