Engineered with Purpose
A comprehensive look at the modern technologies and workflow automations running under the hood of BreezeSlot.
PostgreSQL Exclusion Locking
Leverages btree_gist exclusion constraints in Postgres 18. Both PENDING and BOOKED slots hold their physical interval. Overlaps are blocked at the transaction level before commits occur.
Per-Service Approval Modes
Select INSTANT for automatic confirmation or REQUIRES_APPROVAL for manual holds. Customizable pending expiration window (1 to 72 hours) and lead time guardrails prevent scheduling chaos.
Outcome Verification Queue
Appointments never complete silently in the background. Completed appointments flow into an outcome queue where you confirm attendance, record no-shows, or mark follow-ups within 7 days.
Autonomous Waitlist Backfill
When a booking is canceled, a SLOT_OPENED event fires in the worker outbox. Clients waiting for that provider are alerted immediately. The first client to respond confirms the slot.
Alias-Proof No-Show Shield
Prevents banned or high-risk clients from circumventing blocks using subaddressing (user+alias@gmail.com) or dots. Hashes canonical roots using isolated workspace HMAC keys.
Multi-Channel Outbox
Supports Postmark Email, WhatsApp, and SMS. Background workers handle retries asynchronously with exponential backoff so external gateway blips never slow client booking flows.