Security Engineer in London

Join to apply for the Security Engineer role at Accordion. We are the better way to work in finance. As private equity’s value creation partner, we sit at the heart of PE—where sponsors and CFOs meet. Through financial consulting rooted in data, technology, and AI, we help clients drive value—supporting the office of the CFO to drive end-to-end value creation.

If you crave challenging work and are looking to grow, come solve complex issues alongside 1,400+ finance & technology experts in a supportive, collaborative environment. As we build our European footprint, the London office presents a unique entrepreneurial opportunity to shape our presence and accelerate growth across the region—while benefiting from the support and stability of an established, industry-leading firm.

Role Overview: We are seeking a versatile Security Engineer to join our small, fast‑paced security team. This role supports a wide range of security functions, emphasizing hands‑on technical expertise, proactive problem‑solving, and adaptability across network security, cloud security, incident response, vulnerability management, and security tool administration. This role can be based in our London office with the flexibility to work remotely 1‑2 days a week, blending the best of both worlds for efficiency and collaboration.

What you’ll do:

• Manage and operate our XDR platform: triage alerts, conduct investigations, and take response actions.
• Create security automation through our XDR platform and in our other tools.
• Configure, review, and enhance our SIEM solution.
• Assist with vulnerability management: apply threat modeling of identified CVEs, coordinate technical remediation, propose solutions, and document outcomes.
• Administer email security systems: respond to phishing attempts, maintain and improve filters, investigate suspicious email traffic, and provide quick technical response to threats.
• Deploy, integrate, and maintain diverse security tools: drive lifecycle management, automation of routine security operations, and ensure seamless integration with existing infrastructure.
• Support security awareness and technical training: deliver targeted education and assist users in following security best practices.
• Provide incident response across environments: analyze, contain, document, and automate response processes.
• Collaborate with IT and security leadership to assess risks and prioritize technical security tasks based on business urgency and threat landscape.
• Operate and optimize virtualized Layer 7 firewalls (Palo Alto, Fortinet, Juniper, etc.): configure policies, tune rules, and troubleshoot firewall and traffic anomalies.
• Provide hands‑on support for cloud security operations—design, implement, and monitor Azure networking (with emphasis on Azure Network Security Groups), enforce cloud security best practices, assess cloud risks, and collaborate on secure cloud architecture.
• Administer and optimize network infrastructure, including Meraki environments, with a focus on monitoring, troubleshooting, device configuration, and reviewing network security alerts.
• Manage end‑to‑end network troubleshooting: identify, analyze, and resolve network performance and security issues across LAN, WAN, and cloud‑connected infrastructure.

You have:

• 2+ years of experience in security operations, with demonstrated responsibility for network and cloud environments.
• In‑depth expertise in network management and troubleshooting—including Meraki, multi‑vendor LAN/WAN, and cloud‑connected scenarios.
• Working knowledge of scripting/automation (Python, PowerShell, Bash): ability to streamline security operations, automate repetitive tasks, and integrate systems.
• Proven experience with CrowdStrike (or similar XDR), SIEM platforms, and security tool deployment/integration.
• Hands‑on experience with Azure networking and security groups, with a strong understanding of cloud security requirements.
• Experience with vulnerability management processes, threat modeling, and technical remediation.
• Strong incident response background, including containment, analysis, and reporting.
• Email security expertise (cloud‑based filters, phishing response, suspicious traffic investigation).
• Ability to design and maintain technical controls aligned to compliance frameworks (SOC 2, HIPAA, PCI, etc.).
• Experience supporting user security awareness/training initiatives.
• Experience with virtualized Layer 7 firewall configuration and troubleshooting.

Certifications (preferred):

• CompTIA Network+.
• GIAC Security Essentials (GSEC) or CompTIA Security+.

Nice to have:

• GIAC Continuous Monitoring Certification (GMON).
• GIAC Certified Detection Analyst (GCDA).
• GIAC Defensible Security Architect (GDSA).
• GIAC Certified Enterprise Defender (GCED).
• CISSP (“Associate of ISC2” acceptable).

You are:

• Excited to be part of a growing team, with a focus on driving future growth.
• Experienced in advising clients on financial accounting issues.
• Knowledgeable of complex financial accounting and operations issues.
• Passionate about delivering exceptional client service.
• Experienced in advising clients on financial and transformation initiatives.
• Knowledgeable about the relationship between Private Equity sponsors and their portfolio companies, particularly within the office of the CFO.
• Willing to get your hands dirty in the details of a project while simultaneously seeing the whole picture.
• Comfortable managing projects with multiple complex workstreams while also focused on your single workstream.
• A self‑starter with a strong work ethic.
• Full of entrepreneurial spirit and comfortable in a fluid, flat organization.
• Able to effectively communicate complex issues and solutions, and raise issues to senior team members when necessary.
• A team player, able to work with team members across all levels.
• Someone who enjoys mentoring others and doing meaningful work.
• A leader of others; you lead by example.

Accordion is an Equal Opportunity Employer. We are committed to building a team that represents a variety of backgrounds, perspectives, and skills. We do not discriminate on the basis of race, colour, religion, marital status, age, national origin, ancestry, physical or mental disability, medical condition, pregnancy, genetic information, gender, sexual orientation, gender identity or expression, veteran status, or any other status protected under law.