Built and deployed VYARA, a production multi-tenant shop management SaaS using Next.js, Node.js, Express.js, and PostgreSQL.

Developed 39 REST API endpoints for inventory management, billing, payments, and invoicing.

Designed an 8-table PostgreSQL database schema with 17 indexes and implemented row-level locking to prevent stock inconsistencies during concurrent sales.

Implemented JWT authentication with email verification, password reset, session revocation, and tenant-scoped API access.

Built invoice PDF generation and date-range reports with server-side pagination, search, and filtering.

Deployed the application to production with a focus on secure API design, database reliability, and scalable multi-tenant architecture.