Senior Fullstack Engineer

Senior Fullstack Engineer (AI-First, On-site Warsaw)

Location: Warsaw, Poland

On-site work: 5 days per week (office-based role)

📍About the role:

We are looking for a highly experienced Fullstack Engineer who builds real production systems and actively works with AI as a core part of their daily development workflow.

This is not a remote role and not a junior or mid-level position.

You will work on complex, API-driven systems where architecture, correctness, scalability, and long-term maintainability matter.

Using AI for coding, design, refactoring, and problem-solving (vibe coding) is a hard requirement, not a nice-to-have.

📝What you will do:

• Design, develop, and evolve backend and frontend systems used in production

• Build, extend, and maintain robust APIs (both consuming external APIs and developing internal/public ones)

• Work daily with AI-assisted development tools as an integral part of your workflow

• Make architectural decisions with a focus on scalability, performance, and reliability

• Write clean, maintainable, well-structured code with long-term ownership in mind

• Collaborate closely with other engineers and product stakeholders in an on-site team

• Review, validate, and improve AI-generated code to ensure correctness, security, and performance

📝Must-have requirements:

• Strong, proven experience in software engineering (senior-level or higher)

• Excellent knowledge of:

  ○ JavaScript and TypeScript

  ○ Node.js and modern runtimes such as Bun

• Solid hands-on experience with both React and Vue

• Deep, practical experience working with APIs:

  ○ designing APIs

  ○ extending existing APIs

  ○ integrating third-party APIs

• Strong understanding of software architecture and system design

• High standards for code quality, readability, and maintainability

• Excellent command of AI-assisted development:

  ○ daily use of tools such as Cursor, Copilot, ChatGPT, or similar

  ○ ability to critically assess AI output instead of blindly accepting it

  ○ using AI for refactoring, debugging, testing, documentation, and exploration

• Comfortable working in an English-speaking environment

💎Nice to have

• Experience with DevOps, infrastructure, or production operations

• Experience working on high-traffic or business-critical systems

• Background in designing systems that evolve over time rather than one-off projects

📝Important notes

• his is a full-time, on-site position in Warsaw

• AI-first development is a condition of employment

• We are looking for engineers who think in systems, not just frameworks

• We offer work on a modern application, A close-knit, experienced, and supportive team, private medical care and sports card

  
  

If you prefer remote-only work or do not actively use AI in your daily coding, this role is not a good fit.