MID Java Backend Developer (Node.js / TypeScript)

Position: Mid Java Backend Developer (Node.js / TypeScript)
Location: Hybrid (Warsaw, Poland, 1-2 days/week onsite)
Salary: 100-115 PLN/h
Start: 2 weeks
Contract: B2B / Long-term cooperation

Join a team building high-impact digital solutions used by millions of customers every day. We are partnering with a global leader in telecommunications and digital commerce to expand their Digital Domain team and are looking for experienced Backend Developers ready to work on scalable, modern backend systems powering critical customer journeys. This is an opportunity to contribute to mission-critical BFF (Backend for Frontend) services supporting checkout, customer management, and commerce processes within a large-scale international environment. If you enjoy designing reliable APIs, working with distributed systems, and developing high-quality backend solutions in Java, while also growing within a modern Node.js / TypeScript ecosystem, this role could be the perfect next step in your career.

Responsibilities:

• Design, develop, and maintain scalable backend services using Java 21 and Spring Boot 3.x
• Build and integrate REST APIs and support integrations with multiple internal and external systems
• Work with event-driven and distributed architectures, including asynchronous communication and messaging systems
• Support production environments through monitoring, troubleshooting, observability, and continuous improvement activities
• Collaborate with architects, frontend developers, product teams, and technical leads in agile delivery teams
• Participate in technology transformation initiatives toward Node.js / TypeScript ecosystem
• Write unit and integration tests while ensuring high code quality and resilience standards
• Contribute to production-grade engineering practices, reliability, and maintainability of services

Requirements:

• Commercial backend development experience: MID: 4 years
• Strong expertise in:
  • Java 21
  • Spring Boot 3.x
  • REST API / OpenAPI
  • Spring Security / OAuth2 / JWT
     
• Experience with:
  • API design and system integrations
  • Event-driven architecture and distributed systems
  • Asynchronous flows and messaging concepts
  • Unit and integration testing
  • Monitoring, logging, troubleshooting, and observability
     
• Hands-on knowledge of:
  • MongoDB or similar NoSQL databases
  • Maven or similar build tools
  • Production-grade backend engineering practices
     
• English level: B2 for technical documentation and collaboration

Senior-level candidates should additionally demonstrate:

• Distributed system design experience
• Production ownership and incident resolution
• Mentoring and technical leadership experience
• Technology migration/transformation experience
• Ability to influence engineering standards and best practices

Nice to have:

• Commercial experience with Node.js and TypeScript
• Experience with Express, Fastify, or NestJS frameworks
• Knowledge of Kafka or RabbitMQ
• Experience with Docker and Kubernetes
• Familiarity with GraphQL
• Experience with Terraform and Infrastructure as Code
• Knowledge of OpenTelemetry and distributed tracing
• Experience with Jest or Vitest testing frameworks
• Understanding of npm / pnpm ecosystem

Team structure: Squad within Digital Domain (6-12 developers)

Preferred mindset and personality traits:

• Production Engineer
• Complexity Navigator
• Pragmatic Modernizer
• Status-Quo Challenger
• Collaborative Problem-Solver