Principal Backend Engineer (Node.js / AI / LLM)

Hello,

We are called People More because we treat our employees with respect, but also because the projects we work on are for people and should be easy and pleasant to use. We are technological, but we look at the bigger picture :)

The company is made up of people with a huge client base in the country and abroad, for whom we build projects from scratch (UX, UI, frontend, backend, mobile) or in part. We work directly for our clients and also support our partners in their own solutions. This ensures a wide range of projects and the ability to change! We work with clients all over the world.

For the project that we are working on with our partner, we are looking for Principal Backend Engineer (Node.js / AI / LLM).

Your duties will include:

• Designing and evolving backend architecture for a scalable product
• Developing and maintaining backend services using Node.js, TypeScript and NestJS
• Driving technical and architectural decisions across the platform
• Building event-driven systems and asynchronous processing workflows
• Ensuring security, reliability, observability, and maintainability of services
• Supporting integrations with AI/LLM-powered solutions
• Leveraging modern AI-assisted development tools in daily engineering work
• Collaborating closely with product, frontend, and AI engineering teams
• Contributing to engineering best practices and technical documentation

Requirements that must be met:

• 7+ years of commercial backend development experience
• Strong production experience with Node.js, TypeScript, and NestJS
• Solid PostgreSQL knowledge, including query optimization, indexes, transactions, and working with raw SQL when needed
• Experience building event-driven and asynchronous systems (queues, retries, idempotency, job processing)
• Strong understanding of application security principles, including OAuth 2.0, RBAC/ABAC, OWASP, audit logs, secrets management, and permission boundaries
• Experience designing multitenant architectures, data isolation mechanisms, and RLS-style patterns
• Experience making architectural decisions and documenting them through ADRs (Architecture Decision Records) or similar approaches
• Hands-on experience with AI-assisted software development tools such as Claude Code, Cursor, GitHub Copilot, Windsurf, or similar solutions
• Practical experience with agentic coding, including the use of AI agents for complex development tasks, code generation, review, and iterative refinement
• Ability to effectively collaborate with AI coding agents while maintaining high standards of code quality, security, and maintainability
• Strong leadership skills
• Very good English and Polish

Responsibilities

140 - 190 zł/h