Senior Node.JS Engineer (Nest.JS) (#4117)

Work type : Office / Remote Technical Level : Senior Job Category : Software Development Project : Lebara

Our client is one of Europe's fastest-growing mobile companies with 5 million active customers, 1,000 employees worldwide, and operations in five countries. The client is using the mobile virtual network operator business model.

We are looking for a Senior Backend result-oriented developer who has good knowledge and experience of Nest.js.

Responsibilities :

• Own microservices in NestJS (TypeScript) : define module boundaries, version APIs, and ship resilient, well-tested services.
• Design internal communication : implement REST / gRPC / event-driven patterns (e.g., request / response, pub / sub), handle retries, timeouts, backoff, and circuit breakers.
• Implement secure JWT auth : access / refresh lifecycles, rotation, audience / issuer validation, revocation / blacklisting, and token storage best practices.
• Deliver payment integrations : integrate with gateways (e.g., Stripe / Adyen / Braintree), implement idempotent operations, handle captures / refunds / disputes, and reconcile via signed webhooks .
• Build and consume webhooks : define payload contracts, verify signatures / HMAC, ensure idempotency, and implement robust retry and DLQ strategies.
• Enable real-time features with WebSockets : use NestJS Gateways / Socket.IO or ws for presence, notifications, and fan-out at scale; secure and rate-limit connections.
• Use Redis / Valkey effectively : design cache keys / TTLs, apply cache-aside / write-through, implement distributed locks, queues / streams, pub / sub, and mitigate hot keys.
• Containerize and run locally : craft efficient multi-stage Docker builds, add healthchecks, and orchestrate multi-service dev stacks with docker-compose .
• Quality & reliability : write unit / integration / e2e tests (Jest / Supertest), add schema validation (class-validator / OpenAPI), and instrument with logs / metrics / traces.
• Collaborate across teams : review PRs, write concise design docs, and partner with product, frontend, and data to deliver measurable outcomes.

Requirements :

Nice to have :

We offer