Senior Security Engineer (Europe, Remote)

Company Overview Lumen Dynamics empowers enterprises, government agencies, and other organizations to win the cybersecurity war using the real-time insights about adversaries, their relationships, threat patterns, and imminent attacks relevant to their businesses. The company’s platform collects, interprets, structures, and validates human-led, automation-enhanced intelligence, which fuels our external attack surface and advanced behavioral threat hunting solutions. Customers utilize this operationalized intelligence to drive a proactive response to neutralize threats and mitigate risk. Organizations across the globe leverage Lumen Dynamics ’s world-class intelligence, our trusted practitioner engagement and enablement, and globally-dispersed ground expertise as their frontline guardian against the ever-evolving landscape of cyber threats to fight the adversary — and win. The Role As a Senior Security Engineer you will own and improve the security of our platform, products and engineering delivery process, with a strong focus on application security, secure SDLC, cloud security and customer-facing compliance. This is a hands-on, build-it-yourself role. You will implement controls, fixes, tooling and detections directly - we are looking for a builder who does the work, not an advisor who hands it to others and waits. You will work closely with Engineering, DevOps, Product and QA, and you will manage one internal Security Engineer who owns corporate, identity and endpoint security and supports you on day-to-day compliance. You will report to the Director, Infrastructure & Security. Key Duties and Responsibilities: Product and application security Application security: Lead application security across the product portfolio - threat modeling, secure design reviews, code-review support, and hands-on remediation work alongside developers. Secure SDLC and tooling: Embed security into the SDLC and CI/CD without creating unnecessary delivery friction. Build, own and tune security tooling (SAST, DAST, dependency and container scanning, secrets detection) and implement policy-as-code and pre-merge gates in our Terraform and Terragrunt pipelines yourself. Vulnerability management: Identify, validate, prioritize and remediate vulnerabilities in applications, APIs, infrastructure and third-party integrations, working hands-on with engineering and advising pragmatically on risk trade-offs. Cloud infrastructure and detection Cloud security: Own the security posture across AWS and Kubernetes - IAM and network design, encryption, logging baselines, configuration drift and cloud security posture management. Detection and response: Build and tune cloud detections (CloudTrail, GuardDuty, Security Hub), write runbooks, and act as the technical security lead for product and cloud incidents, partnering with DevOps for investigation and containment. This role is the security escalation point for incidents; there is no primary tier-1 pager rotation. Compliance and customer trust Audit ownership: Own and drive our SOC 2 and ISO 27001 programs end to end - control design, evidence automation and primary auditor liaison - and maintain policies and control documentation in Confluence. The internal Security Engineer runs the day-to-day evidence pipeline and supports you. Customer assurance: Support sales and customer trust by completing security questionnaires, explaining our technical controls, and handling follow-up from customer audits and assessments. Architecture and leadership Security review: Drive the security review of new features, architecture decisions, integrations and platform changes, especially where customer data, authentication, authorization or data-processing risks are involved. Manage and mentor the Security Engineer: Manage, mentor and develop our internal Security Engineer, including 1:1s, performance reviews, leave approvals and day-to-day delegation. Corporate IT, identity and endpoint security are owned by them, not by you, so you can focus on product and cloud security. Education, Experience & Qualifications Ideal Profile Hands-on builder, not an advisor: You implement security yourself - controls, fixes, tooling and detections - rather than handing work to others and waiting for it to happen. This is a doing role. Product and cloud security depth: Strong hands-on background in application security and secure software development in cloud-native environments (AWS, Kubernetes, CI/CD, containers, infrastructure-as-code). Comfortable in code: Comfortable reading code, reviewing APIs and architecture, and working directly with developers on remediation. Compliance driver: Proven ability to drive SOC 2 and ISO 27001 workstreams, from control design to auditor interaction, not only evidence collection. People leadership: Able to manage and develop one engineer, including delegation, 1:1s and performance. Pragmatic communicator: Balances hands-on technical work with the process discipline of enterprise B2B SaaS, and explains ri