Senior Backend Engineer (f/m/d)

We are looking for Senior Backend Engineers (f/m/d) for a variety tribes in Warsaw.
Collaborating closely with designers, product managers and frontend engineers, you will bring innovative ideas to life, helping us build the Finance AI platform for Europe's mid-sized businesses.

Here's a bit more on what you can expect to be doing day-to-day:

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We think you’ll need the following experience and qualifications to succeed in this role: 

• Proven experience as a Backend Engineer, leading projects end-to-end to launch. 

• Proficiency in Java development technologies (incl. Spring framework), as well as latest features and best practices such as microservices, message queue, alerting, reliability and feature flags.

• Understanding of development design patterns and techniques, incl. Rest API design principles.

• Hands-on experience with testing approaches and libraries (unit testing, integration testing).

• You are fluent in English.

In addition, here are the skills and attributes we are looking for:

Moss is the Finance AI platform for Europe's mid-sized businesses, giving companies real-time visibility and full control over their spend. By automating card issuing, invoice management and expenses, Moss simplifies financial workflows and frees finance and accounting teams from manual, administrative work.

Founded in Berlin and used by more than 10,000 businesses including Flink, Schufa, n8n and Auto1, Moss has raised €220+ million to date and operates in Germany, the Netherlands, the UK and further EU markets. In August 2026, Moss closed a €35 million Series C led by Portage, crossing a €1 billion valuation and becoming one of Europe's newest fintech unicorns. Moss is backed by investors including Valar Ventures, Tiger Global, Global Founders Capital, Cherry Ventures, A-Star.

We're a team of 300+ people from 50+ nationalities across 5 offices in Europe and we hire, reward, and grow people based on Moss DNA: playing to win, obsessing over quality, winning as One Moss. If that's how you want to work, we want to hear from you. - here's what else to expect:

• Top-of-market compensation package, including equity. 

• Our vibrant offices are at the heart of our culture, where in-person time fuels collaboration and connection over weekly breakfasts and Friday demos.

• Additional benefits include: 20 days “work from abroad”, 600EUR/GBP Learning & Development Budget, and other local benefits.

Unless stated otherwise, benefits apply to full-time positions (interns and working students receive a tailored package).

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