Senior Product Security Engineer — Remote & Equity

primer.io; United Kingdom; Remote; GBP 90,000 - 130,000; Full time

Benefits offered by this job

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Uncapped holiday

Co-working space access

Workations & Company Retreat

Home office stipend

Private Medical Insurance

Learning budget

Job summary

primer.io, a remote-first payments infrastructure, is hiring a ProdSec/AppSec engineer to join as the second security hire. You’ll help shape the security surface for a payments platform at scale, performing threat modelling, security reviews, and compliance work with SOC2/PCI.

You’ll embed with engineering teams, own projects end to end, build small tools and automation, and communicate clearly with non‑security colleagues. This hands‑on role offers real ownership and growth as Primer scales.

Qualifications

• Experience in product or application security with security reviews or threat modelling.
• Ability to read and write code and build small tools/automation.
• Good judgement about risk and clear reasoning for prioritising risks.
• Ability to plan and deliver work independently and collaborate with senior engineers.

Responsibilities

• Run security reviews and threat modelling on Primer features and systems, turning findings into actionable guidance.
• Independently plan and deliver your own security projects from design to rollout.
• Build tooling and automation to accelerate future reviews.
• Coordinate penetration testing and track remediation to closure.
• Support recurring compliance work (SOC2, PCI) with evidence collection and remediation tracking.
• Contribute to AppSec roadmap initiatives across areas like application threats, AI security, supply chain security, and ASPM.
• Engage in proactive security work and hands-on investigations with product teams.

Skills

Security reviews

Threat modelling

Code reading/writing

Independent work

Communication

Job description

primer.io, a remote-first payments infrastructure, is hiring a ProdSec/AppSec engineer to join as the second security hire. You’ll help shape the security surface for a payments platform at scale, performing threat modelling, security reviews, and compliance work with SOC2/PCI.

You’ll embed with engineering teams, own projects end to end, build small tools and automation, and communicate clearly with non‑security colleagues. This hands‑on role offers real ownership and growth as Primer scales.