Security Engineer III - Detection & Response

The role

You will own detection, investigation, and response for cloud infrastructure and SaaS estate. You will build and tune SIEM detections, automate response workflows, and act as a first responder to security incidents.

What you will do

• Build, tune and maintain detections in Elastic SIEM
• Identify opportunities to onboard new log sources like AWS, Google Workspace, and Kubernetes
• Triage, investigate, escalate and resolve security incidents
• Lead routine incidents end to end and drive larger investigations
• Build runbooks and automations using Python or Tines
• Join the on-call rotation for incident response and monitoring
• Make and document risk decisions
• Keep controls audit-ready for SOC 2 and PCI DSS
• Use AI tools to draft rules, queries, and summarise investigations

Required qualifications

• Real experience responding to security incidents from first alert through to write-up
• Hands-on experience writing and tuning detections in a SIEM (Elastic, Splunk or similar)
• Experience using frameworks like MITRE ATT&CK to reason about coverage
• Experience with cloud-native detection and response in AWS or Google Cloud
• Comfortable with Python or Go for scripting and automation
• Clear, structured written communication

Nice to have

• Experience with Terraform or other infrastructure-as-code
• Experience with no-code security automation or SOAR-style tooling
• Exposure to compliance frameworks like PCI DSS, SOC 2 or ISO27001
• Background in fintech, payments or another regulated industry
• Experience using AI tools or agents in security work

Benefits

• Fully remote and globally distributed
• Competitive share options
• Flexible holiday with 25 days minimum
• 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

Before you apply

• Initial intro call with a Talent Partner
• Interview with the Hiring Manager
• Challenge Stage - Contextualised to the role
• Final, values-alignment interview

About the company

Primer is the unified infrastructure for global payments. They provide visibility and control to finance and payments teams through a single platform.