Booklnk

Overview

● Built the backend from scratch for a booking platform that supports multiple business types (barbershops, gyms, consultants). using NestJS and PostgreSQL. I owned the schema design, API layer, and service architecture ● Integrated Kashier for payments - webhook handling, transaction validation, reconciliation. The usual payment headaches, but got it working reliably ● Slot validation and conflict prevention was a surprisingly tricky problem. Ended up using optimistic locking to handle concurrent bookings