ExtraMiles — Loyalty Microservices Backend

Backend (NestJS Microservices)

About

Distributed microservices backend powering the ExtraMiles loyalty ecosystem — 5 independent NestJS services handling API gateways, core business logic, customer management, and user authentication with MongoDB, Redis queues, and real-time WebSocket channels.

My Role

Architected and built the full microservices platform: backoffice API gateway, client API gateway, core business logic service, customer service, and user authentication service — all with MongoDB persistence, Bull job queues, Firebase push notifications, and AWS S3 asset management.

Core Capabilities

• 5 independent NestJS microservices with clean separation
• Dual API gateways: backoffice (admin) and client (consumer)
• Core service with partner catalogues, discounts, and notifications
• Customer service for loyalty workflows, mileage, and complaints
• User service with role-based access and authentication
• Bull/Redis job queues for async processing

Architecture

• NestJS microservice framework with TCP transport
• MongoDB with Mongoose and pagination plugins
• Redis-backed Bull queues for async workloads
• Firebase Admin SDK for push notifications
• AWS S3 for asset pipelines, Nodemailer for transactional email
• Socket.IO for real-time event channels

Tech Stack