Senior Backend Engineer, International Engineering

Whatnot; Kraków; On-site; PLN 240,000 - 360,000; Full time

Job summary

Whatnot, the largest live shopping platform in North America and Europe, is seeking a Senior Backend Engineer based in Poland. You will design and build scalable distributed systems to support multi-country expansion, partnering with product, operations, payments, logistics, and platform teams.

Initial focus will be on enabling Germany, France, and the UK markets while supporting growth with Polish engineering talent.

Qualifications

• 5+ years of professional software engineering experience
• Strong backend engineering experience in distributed systems or large-scale platforms
• Experience designing, operating, and scaling reliable production services
• Experience working with relational databases and event-driven architectures
• Ability to drive projects independently from ambiguous problem statements to production launch
• Excellent communication skills and ability to collaborate across teams

Skills

Distributed systems

Backend engineering

Relational databases

Event-driven architectures

Independent project drive

Communication skills

Job description

Join the Future of Commerce with Whatnot!

Whatnot is the largest live shopping platform in North America and Europe to buy, sell, and discover the things you love. Whether it's trading cards, fashion, electronics, or live plants, our sellers are building real businesses across hundreds of categories. We're building live commerce at a scale that's never been done in the West, and there's no playbook to copy. The people here are shaping how an entirely new industry develops.

Role

The International Engineering team at Whatnot builds the foundational systems that power our global expansion. Every new market introduces different payment methods, tax requirements, shipping constraints, consumer protections, and operational challenges, creating complex technical problems with direct business impact.

As a Senior Backend Engineer based in Poland, you'll work with a small, high-impact team across Poland and the US to design and build highly scalable distributed systems that support millions of transactions across multiple countries and regulatory environments. You'll partner closely with product, operations, payments, logistics, and platform teams, with an initial focus on Germany, France, and the UK.

The team owns critical operational and transactional systems across:

• Cross-border transaction infrastructure
• Tax and regulatory compliance
• International post-purchase experiences
• Marketplace operational tooling and automation

Your work will span core backend infrastructure and product-facing systems that directly improve buyer trust, seller success, and Whatnot's ability to scale globally.

You

Required

• 5+ years of professional software engineering experience
• Strong backend engineering experience in distributed systems or large-scale platforms
• Experience designing, operating, and scaling reliable production services
• Experience working with relational databases and event-driven architectures
• Ability to drive projects independently from ambiguous problem statements to production launch
• Excellent communication skills and ability to collaborate across engineering, product, operations, and business stakeholders

Preferred

• Strong proficiency in Python
• Experience with payments, fintech, e-commerce, logistics, marketplace platforms, or compliance systems
• Experience building operational platforms, workflow systems, or transaction processing infrastructure
• Experience working in rapidly growing product organizations

Please note: Whatnot will only contact you through official @whatnot.com email addresses. If you see an email impersonating a Whatnot recruiter, please disregard and report it as spam.

EOE

Whatnot is proud to be an Equal Opportunity Employer. We value diversity, and we do not discriminate on the basis of race, religion, color, national origin, gender, sexual orientation, age, marital status, veteran status, parental status, disability status, or any other status protected by local law. We believe that our work is better and our company culture is improved when we encourage, support, and respect the different skills and experiences represented within our workforce.