Senior Node Developer

We are looking for a high-impact Backend Developer for a 3-to-6-month external support mission. Our client is currently building a dedicated team to handle card transactions. While they scale their in-house team, they need an expert to step in immediately to bridge the gap and deliver value from the first week. This isn't a project for "greenfield" specialists; we need someone who understands the complexity and maturity of large-scale, production-ready systems.

Details

• Duration: 3 – 6 months (Short-term, high impact).

• Start Date: ASAP 

• Tech Stack: Node.js, TypeScript, Fastify.

• Architecture: Microservices, Event-driven, Pub/Sub.

Responsibilities

• Core API Development: Build and scale APIs focused on card transaction processing.

• System Integration: Execute complex integrations with external card processors.

• Banking Integration: Connect and sync with internal core banking systems.

• Architectural Maintenance: Maintain and evolve a mature, distributed ecosystem using Webhooks and Pub/Sub patterns.

Requirements

• Distributed Systems Mastery: You don't just "integrate" with event-based architectures; you know how to build, scale, and troubleshoot them. Deep knowledge of concurrency, consistency, and fault tolerance is non-negotiable.

• Fastify & Node.js: Strong commercial experience with Fastify and TypeScript in a microservices environment.

• Mature Project Experience: Proven track record in large, mature, and complex enterprise projects. We are looking for someone who knows how to navigate "brownfield" environments and follow established standards without a long ramp-up period.

• Proactive Autonomy: The ability to understand the business domain quickly and start executing tasks without constant supervision.