Senior Software Engineer - Zagreb

About Engineering at Fonoa

Engineering is central to how we build the business. We focus on solving real customer problems, not just shipping features. We work in small, high-trust teams, with full ownership across the lifecycle, from design to production and beyond.

We value:

• Ownership – engineers own what they build end-to-end
• Simplicity – we break down complex problems into clear solutions
• Thinking Big - we innovate with modern technologies (LLMs, AI Agents, etc.) to solve meaningful problems
• Quality – scalable, maintainable systems are non-negotiable
• Speed & iteration – we ship fast, learn, and improve continuously
• Collaboration – we win as a team, not as individuals

Position Overview

As a Staff Engineer, your role is to improve the system as a whole, both technically and organizationally.

You will work on ambiguous, high-impact problems, shape technical direction across teams, and help others build better systems. Your impact comes less from the code you write, and more from how you influence decisions, design, and execution at scale.

What You Will Do

• Take ownership of complex, cross-team problems that are not clearly defined
• Define technical direction and drive system design across domains
• Identify and address systemic issues and opportunities early
• Simplify complexity through better architecture, patterns, and structure
• Improve how teams build by raising standards, tooling, and practices
• Mentor engineers and contribute to hiring and team growth
• Ensure systems are reliable, scalable, and built for long-term evolution

What Good Looks Like

• You focus on high-leverage problems and shape how they are approached
• You create clarity in ambiguous situations and align teams around it
• You improve not just code, but how teams design and build systems
• You make others more effective through guidance, feedback, and direction
• You operate with long-term thinking, balancing today’s needs with future scale
• You adopt emerging AI technologies and create a culture of innovation in your teams

At this level, you are expected to “make the whole system, and the people in it, better.”

What We’re Looking For

• Strong experience designing and operating scalable backend systems
• Proven ability to work on ambiguous, high-impact problems
• Track record of influencing technical decisions beyond your team
• Ability to balance speed, quality, and long-term maintainability
• Experience mentoring engineers and improving team practices
• Fostering a culture of curiosity and experimentation

API Documentation

For engineers, API design and structure are an important part of evaluating a role. You can explore our API and how we build products here

Tech Stack

We use these technologies today, but we don’t hire for specific tools. We care about engineers who can understand problems, make good technical decisions, and choose the right tools for the job.

• Backend: Node.js, Go
• Frontend: React, TypeScript
• Infrastructure: GCP, k8s, Terraform, Postgres

Note: If you don’t think you have the full experience we’re looking for, but you could be a fit and are willing to learn, do apply anyway! We are building a diverse and inclusive team.