Senior Back-End Developer (Warsaw)

🚀 Senior Back End Engineer (Node.js): Shape the Backend of a Global B2B Platform

The challenge:

Picture an enterprise platform used by customers worldwide, processing huge volumes of data through distributed systems where performance, scalability, and reliability aren’t nice-to-haves but the baseline.

Our client is an established international technology company building a sophisticated B2B software platform. The environment is data-intensive and complex: mature production systems live side by side with ongoing innovation. The team is constantly developing new capabilities, optimizing existing services, and improving the underlying architecture.

Your role:

We’re looking for an experienced Senior Back End Engineer to join a product engineering team working on large-scale software systems. The role is predominantly backend, with occasional frontend work when a project needs it.

You’ll take end-to-end ownership of your solutions: from requirements analysis and system design to implementation and deployment. You’ll collaborate with cross-functional teams, influence architectural decisions, and work with a high degree of autonomy. We’re looking for someone independent and proactive, with strong technical judgment and a product-oriented mindset.

What you’ll do:

• Build and maintain scalable production services in TypeScript and Node.js
• Own system-design decisions for new capabilities and integrate them with existing infrastructure
• Turn product and engineering requirements into effective technical solutions
• Design and optimize PostgreSQL queries, indexes, and database performance
• Contribute to React frontend work when the project calls for it
• Work with DevOps on deployments, observability, capacity, and production readiness
• Handle feature development, bug fixes, security improvements, and production patches
• Evaluate architectural alternatives and communicate trade-offs in business terms
• Use AI development tools daily for planning, coding, and testing

• Join the on-call rotation and help resolve critical production issues

   

What you bring

• 5+ years of backend development on production systems at scale, with a solid understanding of distributed systems
• Strong hands-on TypeScript and Node.js expertise
• Solid system-design skills and the ability to explain decisions and trade-offs
• Strong PostgreSQL skills: complex queries, optimization, indexing, performance tuning
• Familiarity with React and willingness to work on the frontend when needed
• Familiarity with CI/CD, Docker or Kubernetes, and observability
• Ability to work independently and collaborate across teams
• Product-oriented thinking that connects technical choices to business and user needs

• Practical experience with AI-assisted development tools

   

Bonus points:

✦ Microsoft Azure or another major cloud platform
✦ Redis, Elasticsearch, or ClickHouse
✦ Deeper DevOps experience: infrastructure and deployment workflows

Why us:

• 20 days of vacation per year, plus official national holidays in your country of residence
• Full accounting and legal support in all countries where we operate
• A powerful workstation and access to coworking space when needed

If you want real ownership, interesting scale, and a say in how the system evolves, let’s talk.