Senior Engineer, Backend - Protection
Confirmed on the employer's own hiring board on Oct 30, 2026. First seen by Alion on Oct 27, 2026. Primer scores A on the Alion truth index.
An Introduction to Primer
Primer is the unified infrastructure for global payments. We give finance and payments teams the visibility and control to reduce complexity, improve performance, and capture more revenue - all from a single platform.
Backed by Sofina, Peak XV Partners, ICONIQ, Tencent, Accel, and Balderton, we're building the payments layer the world's best companies rely on.
Learn more about our culture >
Which team will you be joining?
We play a key role in helping merchants handle disputes and prevent fraud. The Protection team owns the risk management suite that surfaces these threats, and helps merchants build automation to handle them at scale.
What will you be doing?
Move across the backend and, where needed, support development of our new dashboard frontend
Architect and build the automation merchants need to handle payment disputes at scale: notification, deadline tracking, evidence collection, responses
Expand our dispute coverage from five PSPs to the rest of Primer's network
Work directly with third-party fraud vendors (Riskified, Forter, Signifyd, Sift) to build a unified comparison and switching experience, rather than the current bolt-on integration
Design and ship the native rules and signals engine like velocity rules, blocklists, device fingerprinting, as automation merchants configure directly
Make early architecture calls - service boundaries, integration patterns, data model, that decide how well this automation scales as more merchants and PSPs come online
Partner closely with the EM and Product to turn merchant pain (invisible disputes, missed fraud signals) into automation that ships, not just tickets
What we're looking for
Experience owning backend systems end-to-end; design through shipping through monitoring - ideally in fraud, risk, payments, or another consequential space
Comfortable designing systems from scratch
Strong architecture and code-quality instincts
Experience mentoring or raising the technical bar for people around you
Proactive and looking to ship early and often-you drive work into customers' hands quickly rather than polishing indefinitely
History of setting and maintaining a high bar for quality in shipping-missing disputes because of bugs costs our customers real money
Nice to have, not required
Exposure to card scheme rules, chargeback workflows, or fraud vendor integrations
Experience with webhook-based event systems, rules engines, or orchestration platforms
Willingness to pick up frontend work as needed
What you should know
This team is new enough that some structure-on-call rotas, tooling, conventions, you'll be building it alongside doing the actual work
Real ambiguity in the early days: you will be the one deciding what "good" looks like before anyone else has an opinion
A handful of people today, so your individual output is highly visible
A typical interview process
An initial intro call with a Talent Partner
An interview with the Hiring Manager
Challenge Stage - Contextualised to the role
A final, values-alignment interview
What's the culture like at Primer?
We're building a culture where people can do their best work and be proud of the impact they have. You'll be working with people who are mission-driven, smart, and reflective, and who are genuinely invested in building exceptional products and delivering success for our merchants.
We work remotely, and have done since day one. We believe that building a successful, profitable company goes beyond proximity. We invest in our relationships through great remote working practices and thoughtfully designed face-to-face time, including workations, our annual company retreat, and access to co-working spaces across most major cities.
The work is challenging. Scaleups are a challenge, and building category-defining products is a challenge. But there's a meaningful difference between a challenge and a struggle. At Primer, the right challenge comes with the right support: strong onboarding, a collaborative environment, and a team that is genuinely invested in your success. It's never something you face alone.
Our benefits
We are fully remote and globally distributed; and have been since day one
Competitive share options
Flexible holiday, with 25 days minimum to be taken
Co-working space access across major cities
Workations & Company Retreat
The best equipment for your role
£500 towards your home office setup
Generous learning budget
Private Medical Insurance
A broad set of additional perks and benefits (depending on location)
Don’t meet every single requirement?
At Primer, we're dedicated to building a diverse, inclusive, and authentic workplace. If you're excited about this role but your experience doesn't align perfectly with every qualification listed, we encourage you to apply. You may be the right candidate for this or other roles.
Primer is committed to the equal treatment of all current and prospective employees and adopts a zero-tolerance approach to discrimination, regardless of age, disability, sex, sexual orientation, pregnancy and maternity, race or ethnicity, religion or belief, gender identity, marriage and civil partnership, or any other background or belief.