Senior/Staff Backend Engineer

About the role

Qonto is seeking a Senior or Staff Backend Engineer to join our mission of building the financial infrastructure that empowers 600,000+ European SMEs to succeed every day. In this role, you will own the design, reliability, and scalability of services that handle real financial transactions in real time, where precision and robustness are non-negotiable. You will co-own service architecture guided by Domain-Driven Design, ensuring our systems remain resilient as we grow across Europe. You are expected to lead technical discussions, mentor engineers, and drive post-mortems that turn incidents into lasting improvements. This is a role for someone who experiments with AI, questions its output, and pushes automation further while maintaining strict standards for quality. You will be part of a diverse, merit-based community where your skills and potential define your trajectory, not your background. Together, we build the freedom for SMEs to succeed, and your work will be felt by thousands of businesses across France, Germany, Italy, Serbia, and Spain.

Key facts

What you'll do

Architect and maintain backend services that process real-money financial transactions with zero tolerance for error, owning reliability from design through production.

Co-own service architecture and data models using Domain-Driven Design to ensure scalability, clarity, and long-term maintainability.

Lead technical design discussions, anticipate risks, and mentor junior and mid-level engineers to elevate the entire squad.

Drive continuous improvement by identifying flaky tests, fixing CI issues, and running blameless post-mortems that generate actionable learnings.

Transfer quickly onto our primary languages of Go and Ruby, and our platform based on Kubernetes on AWS with PostgreSQL and Kafka.

Leverage AI tools such as Cursor or Copilot to raise the bar on code quality, debugging, and system understanding, not just speed.

Own the full lifecycle of features, from slicing requirements with product teams to monitoring service health and iterating post-release.

Collaborate closely with frontend, mobile, and product teams in cross-functional squad environments to align on mission goals.

Implement and evolve quality practices such as testing, monitoring, and alerting to keep our financial services robust and observable.

Champion security and compliance considerations in every design, ensuring that customer data and money movements are always protected.

Translate business needs into technical roadmaps, balancing delivery speed with technical debt management and long-term platform health.

Act as a pragmatic leader who unblocks peers, documents decisions, and propagates best practices across the 190-strong backend community.

Requirements

You must have strong backend engineering experience with exposure to large-scale web application architecture and real production constraints.

You must be fluent in transferring to new technologies and comfortable working with similar stacks to Go, Ruby, Kubernetes, AWS, PostgreSQL, and Kafka.

You must write tests, set up monitoring, handle incidents methodically, and perform root cause analysis to prevent recurrence.

You must track impact after release, flag regressions, and proactively improve the parts of the system within your ownership.

You must be comfortable working in squad teams with Product Managers, Designers, and engineers from frontend, mobile, and other backend stacks.

You must be fluent in English to collaborate effectively across European offices and distributed teams.

You must demonstrate ownership by leading design discussions, mentoring peers, and driving continuous improvement without waiting for direction.

You must align with Qonto's culture of merit-based hiring, diversity, and discrimination-free collaboration.

Nice to have

Experience contributing to open source or building tools that improved team productivity.

Previous work in finance or regulated environments where security and compliance are critical.

Practical notes

This role is based in Berlin, Germany, and is open to professionals living in or willing to relocate to Germany, France, Italy, Serbia, or Spain.

This is a full-time engagement aligned with Qonto's mission to scale financial infrastructure across Europe.