Senior Backend Engineer - Protection

About the role

Primer is the unified infrastructure for global payments, and its Protection team owns the risk management suite that surfaces payment disputes and fraud threats and helps merchants automate their handling. This is a full-time, fully remote Senior Backend Engineer position on a new team, where you will help build the automation merchants need to handle disputes at scale.

Key responsibilities

• Move across the backend and, where needed, support development of a new dashboard frontend.
• Architect and build automation for payment disputes: notifications, deadline tracking, evidence collection and responses.
• Expand dispute coverage from five PSPs to the rest of Primer's network.
• Work with third-party fraud vendors (Riskified, Forter, Signifyd, Sift) to build a unified comparison and switching experience instead of bolt-on integrations.
• Design and ship the native rules and signals engine, such as velocity rules, blocklists and device fingerprinting.
• Make early architecture decisions on service boundaries, integration patterns and data model.
• Partner with Engineering Management and Product to turn merchant pain points into shipped automation.

Required profile

• Experience owning backend systems end-to-end, from design through shipping through monitoring, ideally in fraud, risk, payments or a similar space.
• Comfortable designing systems from scratch, with strong architecture and code-quality instincts.
• Experience mentoring others or raising the technical bar.
• Proactive, eager to ship early and often, with a history of maintaining a high bar for quality.
• Nice to have: exposure to card scheme rules, chargeback workflows or fraud vendor integrations; willingness to pick up frontend work as needed.

What we offer

• Fully remote, globally distributed work since day one.
• Competitive share options.
• Flexible holidays, with a minimum of 25 days.
• Co-working space access across major cities, workations and a company retreat.
• £500 towards a home office setup and a generous learning budget.
• Private medical insurance and additional location-dependent perks.