John  Rostern

Vice President - Cybersecurity & Digital Forensics

Marcum Technology

About John

John Rostern is the Vice President of Cybersecurity and Digital Forensics at Marcum Technology. He leads a team of professionals who assist clients in effectively managing cyber risk, securing their information assets, and achieving compliance with legal and regulatory standards.

John brings over 40 years of professional experience to Marcum. His experience includes working successfully with clients across all industry sectors including cloud service providers, social media, entertainment, financial services, healthcare, manufacturing, aviation/aerospace defense, and technology.

John and his team work closely with clients to deliver a wide range of services to assist them in effectively managing cyber risk. Services provided by the team include Governance Risk and Controls (GRC), Security Operation Center (SOC), and Security Engineering and Technical Services such as penetration testing, attack surface mapping, threat hunting, and vulnerability scanning.

Professional & Civic Affiliations

  • Information Systems Audit and Control Association (ISACA)
  • Information Systems Security Association (ISSA)
  • Institute of Internal Auditors (IIA)
Practice Focus

Attack Surface Management
Cybersecurity Controls Maturity
Governance Risk & Controls (GRC)
Penetration Testing
Risk Assessment
Security Engineering
Security Operations Center (SOC)
Threat Assessment
Vulnerability Assessment

Industry Focus

Aviation/Aerospace Defense
Cloud Service Providers (CSP)
Financial Services & Insurance
Information and Entertainment
Private Equity
Social Media


Bachelor of Business Administration, Finance
Hofstra University