Excalibur Integration Middleware
Educational ERP ↔ SAP Business One — NestJS API Middleware
A NestJS backend middleware I designed and built 100% solo, bridging the Excalibur educational ERP with SAP Business One. It handles the full financial data pipeline — student records, down-payments, payments, revenue invoices, credit notes, GL accounts, and bank reconciliation — running in production on a PM2-managed Linux server.
My Role
I am the sole developer of this middleware — 100% of the architecture, implementation, and deployment. I designed the SAP Business One integration layer, built all API endpoints, set up the PM2 production environment, and maintained the system across multiple release versions (V1.0.0 → V1.1.1).
Modules Built
Student Management
Create, update, and retrieve student records in SAP Business One
Bidirectional sync of student profiles and enrolment data
Master data management for GL accounts and reference data
Payment Processing
Down-payment creation and cancellation with foreign currency support
Incoming payment recording and reconciliation
Outgoing payment handling
Unprocessed and cancelled payment tracking
Invoicing & Credit Notes
Revenue invoice generation synced to SAP B1
Credit note creation and management
GL account mapping for financial accuracy
Infrastructure & Auth
JWT + RBAC authentication layer
PM2 process management for production stability
AWS S3 file storage integration
Office365 SMTP email notifications
MongoDB audit logging for all sync operations
NestJS Throttler rate limiting (later optimised)
Tech Stack
Framework
Database
Integration
Auth & Security
Infrastructure
Dev
Designed & built 100% by Nisala Nadeera Kudaligamage — Full-Stack Software Engineer