Senior Cybersecurity Engineer

Larson Network Services, LLC is seeking a Senior Cybersecurity Engineer to help build and drive cybersecurity initiatives across security engineering, security operations, compliance, and security awareness. This onsite role in St. Louis, MO focuses on practical security outcomes, including tool development and automation, monitoring and incident response, and maintaining the policies and controls that support reporting and continuous improvement.

What you’ll do

• Design and build security controls across endpoint, identity, network, and cloud environments, including Microsoft Azure and Entra ID.
• Research and evaluate security tools, then develop recommendations, business cases, proofs of concept, vendor assessments, and deployments for selected solutions.
• Build detection logic, automation, and response playbooks.
• Perform threat modeling and security reviews for new systems, changes, and projects, recommending mitigations.
• Develop and improve security baselines and hardening standards.
• Integrate security tooling to reduce manual work, including automating phishing triage, phishing campaign reporting, and vulnerability ticketing.
• Use AI tools, APIs, and low-code automation to connect security and SaaS platforms (for example EDR, vulnerability management, phishing simulation, Microsoft 365, Entra ID, and ticketing) and consolidate data.
• Create and maintain dashboards and reports for security monitoring, including vulnerability, phishing, incident, and compliance metrics.
• Monitor, investigate, and respond to security alerts and incidents, including phishing emails, malware alerts, and unauthorized access attempts.
• Administer and maintain security tools such as EDR and vulnerability scanners.
• Remediate incidents, conduct follow-up analysis, document findings and actions taken, and recommend process improvements.
• Manage phishing reports submitted by staff, coordinate containment and communication, and tune detections to reduce false positives and manual triage.
• Run recurring phishing simulation campaigns and analyze outcomes to identify departments or individuals needing additional training or follow-up.
• Develop and deliver security awareness communications, training materials, and coaching based on simulation outcomes and leadership direction, and maintain training completion records.
• Support day-to-day compliance efforts, conduct periodic control assessments, gather evidence, and help close compliance gaps.
• Draft and maintain security policies, standards, procedures, risk assessments, and control inventories, mapping controls to applicable frameworks and recommending improvements.
• Support internal and external audits and regulatory examinations by preparing evidence packages and responding to inquiries.
• Provide systems administration support as assigned, including user account management, access provisioning, Conditional Access policies, and endpoint configuration; assist with service desk escalations requiring elevated access.
• Collaborate with Larson Technology Services colleagues on infrastructure projects with a security-first perspective for system design and change management.

What you’ll bring

• Bachelor’s degree in Cybersecurity, Computer Science, Information Systems, or a related field, or equivalent professional experience.
• 8+ years of hands-on cybersecurity engineering experience, including at least 3 years at a senior or specialist level.
• Proven experience owning security compliance work aligned to frameworks such as NIST CSF, NIST SP 800-53, ISO 27001, SOC 2, or CIS Controls, including audit preparation and evidence management.
• Deep experience architecting, deploying, and optimizing security tools such as EDR/XDR and vulnerability management platforms, including tuning, policy design, and integration.
• Advanced proficiency building automation and tooling with scripting languages such as PowerShell and Python.
• Strong SIEM and detection engineering experience, including detection rule development, data source correlation, and mapping detections to MITRE ATT&CK.
• Experience applying AI tools and APIs to connect systems, automate workflows, and build dashboards or reports with sound judgment about data handling and risk.
• Extensive hands-on experience securing Microsoft Azure and Entra ID, including Conditional Access, identity governance, privileged access management, and cloud security posture.
• Experience authoring and maintaining security policies, standards, and procedures.
• Experience running phishing simulation platforms and security awareness programs, including effectiveness measurement and reporting.
• Demonstrated ability to lead incident investigations and clearly communicate findings and risk to technical teams, executives, and non-technical audiences.
• Ability to evaluate security solutions, build business cases, and present recommendations to management and leadership.
• Ability to manage multiple competing priorities independently in a fast-paced environment.
• Experience mentoring and providing technical guidance to technology staff.

Technology focus

• Microsoft Azure, Entra ID, Microsoft 365
• EDR, XDR, vulnerability management, phishing simulation, ticketing
• AI tools, APIs, low-code automation
• PowerShell, Python
• SIEM, MITRE ATT&CK
• NIST CSF, NIST SP 800-53, ISO 27001, SOC 2, CIS Controls
• Conditional Access, identity governance, privileged access management, cloud security posture
• Microsoft SC-200, AZ-500

Preferred qualifications

• Relevant certifications such as CISSP, CISM, CISA, GCIH, CompTIA Security+, CEH, or Microsoft SC-200 or AZ-500.
• Experience with security architecture reviews, risk assessments, or third-party and vendor risk management.
• Experience with infrastructure as code or DevSecOps practices.
• Familiarity with financial services regulatory requirements, including SEC and FINRA cybersecurity expectations such as Regulation S-P and GLBA.