Software Engineer, Fraud

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. We’re re-defining e-commerce by blending community, shopping, and entertainment into a community just for you. As a remote co-located team, we’re inspired by innovation and anchored in our values. With hubs in the US, UK, Germany, Ireland, and Poland, we’re building the future of online marketplaces –together.

From fashion, beauty, and electronics to collectibles like trading cards, comic books, and even live plants, our live auctions have something for everyone.

And we’re just getting started! As one of the fastest growing marketplaces, we’re looking for bold, forward-thinking problem solvers across all functional areas. Check out the latest Whatnot updates on our news and engineering blogs and join us as we enable anyone to turn their passion into a business, and bring people together through commerce.

The Trust and Risk, Fraud, and Integrity teams at Whatnot are responsible for building systems that help set clear expectations, encourage good behavior, and address issues fairly and efficiently. By combining proactive detection with transparent enforcement, we ensure Whatnot remains a safe and trustworthy place for both buyers and sellers.

We focus on:

• Policy enforcement and dispute resolution
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  Designing systems that set clear behavioral expectations, detect and address policy violations, and resolve disputes efficiently.
• Reusable, high-performance platforms
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  Building and maintaining scalable infrastructure that powers internal operations, automated and manual actioning systems, and advanced detection capabilities.
• Intelligent detection and prevention
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  Leveraging machine learning, behavioral analysis, and real-time interventions to stay ahead of evolving abuse patterns and protect both buyers and sellers.
• Continuous improvement
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  Using feedback loops and monitoring systems as managed assets for ongoing quality assurance and for strengthening algorithms, methodologies, and operational processes.

Together, these teams ensure Whatnot remains a trusted, safe, and thriving marketplace for all users.

Team members in this role are required to be within commuting distance of our Los Angeles, San Francisco, New York, and Seattle hubs.

• Design and develop systems to protect the platform
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  Build and iterate on production algorithms and infrastructures that mitigate systemic risks and safeguard buyers, sellers, and the broader Whatnot community.
• Balance risk and user experience
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  Proactively monitor the impact of protective systems on trusted users, ensuring interventions deliver more value than friction.
• Respond in real time to threats
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  Architect event-driven pipelines and detection frameworks that enable near real-time responses to high-risk user behavior.
• Contribute across the full development lifecycle
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  Engage in ideation, scoping, prototyping, load testing, deployment, and monitoring to deliver resilient and scalable solutions.
• Drive cross-team initiatives
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  Collaborate across multiple product surfaces and operational teams, surfacing insights to leadership and stakeholders through dashboards, notebooks, and clear written documentation.
• Continuously evolve defenses
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  Stay ahead of emerging abuse patterns, abuse vectors, and account integrity risks by iterating quickly and rigorously testing solutions.

The salary range may be inclusive of several levels that would be applicable to the position. Final salary will be based on a number of factors including, level, relevant prior experience, skills, and expertise. This range is only inclusive of base salary, not benefits (more details below) or equity.

Curious about who thrives at Whatnot? We’ve found that low ego, a growth mindset, and leaning into action and high impact goes a long way here.

As our next Software Engineer you should have 7+ years of total software engineering experience, plus:

• Bachelor’s degree in Computer Science, Statistics, Applied Mathematics, Economics, a related technical field, or equivalent work experience.
• 4+ years of software engineering experience building…