Backend Engineer (Node.js/TypeScript) at Tezza Business Solutions Ltd

We are looking for a Mid to Senior Backend Engineer to join our hybrid work team and to own the architecture of our "Growth Engine." You will move beyond simple CRUD APIs to build complex Event-Driven Systems, Offline Sync Protocols, and High-Volume Marketing Queues.
You will work closely with the Solution Architect and the rest of the development team to ensure our platform is fast, resilient in low-bandwidth environments, and capable of delivering real-time Customer Intelligence (CI).

Key Responsibilities

• Core Architecture: Lead the migration of our Modular Monolith (Express.js) towards a structured, Service-Oriented architecture (NestJS/TypeScript) to support scale.
• High-Volume Queues: Design and implement robust background job processing using Redis & BullMQ to handle marketing blasts (SMS/WhatsApp/Email) without blocking the main API thread.
• Offline Synchronization: Build the "Sync Service" that handles data conflict resolution and delta updates between our MongoDB backend and the React Native (WatermelonDB) mobile app.
• Customer Intelligence Engine: Write complex MongoDB Aggregation pipelines to calculate real-time RFM (Recency, Frequency, Monetary) scores and Customer Health metrics.
• Integrations: Build secure, scalable integrations with third-party providers including Paystack/Flutterwave (Payments), Meta Graph API (Social), and Africa’s Talking (SMS).
• API Design: Develop flexible GraphQL and REST endpoints that allow our frontend to fetch "Customer 360" data efficiently.
• Quality & Security: Enforce TypeScript strict typing, write comprehensive unit/integration tests (Jest), and ensure multi-tenant data isolation at the middleware level.

What We Are Looking For

Technical "Must Haves":

• 4+ years of backend engineering experience with Node.js.
• TypeScript Expert: You don't just use any; you understand generics, interfaces, and strict type safety.
• Database Mastery: Deep experience with MongoDB (Schema design, Indexing, and Aggregation pipelines). You know how to model data for performance.
• Message Queues: Proven experience with Redis (caching and queuing with BullMQ/Sidekiq equivalent).
• API Standards: Strong grasp of RESTful principles and GraphQL schema design.