Senior Backend Engineer — Real-Time Node.js, Paris

The French Sourcer; Paris; On-site; EUR 90,000 - 120,000; Full time

Benefits offered by this job

Health insurance

Profit-sharing

Employee incentive scheme

Job summary

The French Sourcer is seeking a Senior Backend Engineer to own and evolve a real-time distributed platform in Paris. You will design and operate high-throughput backend services, build scalable microservices with Node.js/TypeScript, and create robust APIs and data models across the product line.

You will implement event-driven workflows, optimize performance and concurrency, and shape caching, DB access, and deployment through CI/CD.

Qualifications

• 5+ years of experience building and operating backend services in production.
• Strong experience with JavaScript or TypeScript and Node.js.
• Experience designing microservices and event-driven systems.
• Good understanding of distributed system failure modes.
• Experience building services that handle high request or message volumes.
• Strong knowledge of relational databases, data modelling, indexing, and query optimisation.
• Understanding of transactions, locking, concurrency, and data consistency.
• Experience designing and operating caching layers.
• Practical knowledge of containers, CI/CD, and cloud infrastructure.
• Experience with monitoring, logging, tracing, and production incident investigation.
• Ability to evaluate performance, availability, and maintainability trade-offs.
• Experience using Git, code reviews, and automated testing.

Responsibilities

• Designing and building highly available backend services for a real-time transactional platform.
• Developing scalable microservices using server-side JavaScript and Node.js.
• Building APIs and data models used across the wider platform.
• Designing event-driven workflows for authentication, flow control, routing, and asynchronous messaging.
• Improving application performance, concurrency handling, and resource usage.
• Designing caching strategies while managing consistency and invalidation constraints.
• Optimising relational database queries, indexes, transactions, and locking behaviour.
• Building automated tests covering functional behaviour, integration, performance, and failure scenarios.
• Running load and stress tests based on real production traffic patterns.
• Deploying containerised services through automated CI/CD pipelines.
• Implementing monitoring, logging, tracing, and alerting for production services.
• Investigating incidents across application code, databases, messaging systems, and infrastructure.
• Evolving critical services without interrupting a live platform used by hundreds of thousands of active users.

Skills

Node.js

JavaScript/TypeScript

Microservices

Event-driven

Relational databases

Caching

CI/CD

Cloud

Monitoring/Tracing

Incident response

Tools

Docker

Kubernetes

Job description

The French Sourcer is seeking a Senior Backend Engineer to own and evolve a real-time distributed platform in Paris. You will design and operate high-throughput backend services, build scalable microservices with Node.js/TypeScript, and create robust APIs and data models across the product line.

You will implement event-driven workflows, optimize performance and concurrency, and shape caching, DB access, and deployment through CI/CD.