Company Details
Technology Stack
Professional Summary
Gunnar Siebert is Head of M&A Cyber DACH at Aon. Aon operates in the financial services industry and has 60000 employees. Based in Berlin, Berlin, Germany. Classified as a head-level Head of Security leader. Their organization's technology stack includes Cloudflare DNS, Outlook, CloudFlare Hosting, Microsoft Azure Hosting, DemandBase, and 73 other technologies. Aon reports annual revenue of 15698000000.
Industry & Role Insights
- • CTO Rank tracks 708 Head of Security leaders with verified contact information.
- • There are 34,741 tech leaders in the financial services industry in our database.
- • We have verified contacts for 60 tech leaders at Aon.
- • 4,166 tech leaders in Berlin are available in our database.
Position in the CTO Rank Database
- • Gunnar Siebert is 1 of 713 leaders with the Head of Security role tracked in the CTO Rank database.
- • 73 hold the Head of Security role at financial services companies (out of 34,954 total financial services leaders in our database).
- • 3 hold the Head of Security role in Berlin.
- • 11 hold the Head of Security role at companies with 60000 employees.
Data compiled from LinkedIn public profiles, company filings, and verified public technology signals. Methodology & sources · Updated May 2026.
Frequently Asked Questions
How do I contact Gunnar Siebert?
Gunnar Siebert has a verified email address on file on CTO Rank. They work at Aon. Pro members can access direct email addresses, LinkedIn profiles, and phone numbers.
What company does Gunnar Siebert work for?
Gunnar Siebert is Head of M&A Cyber DACH at Aon, a company in the financial services industry with 60000 employees. The company is headquartered in England, United Kingdom.
What is Gunnar Siebert's role in technology leadership?
Gunnar Siebert is classified as a Head of Security leader at the head level.
What technologies does Gunnar Siebert's organization use?
Gunnar Siebert's organization uses a technology stack that includes Cloudflare DNS, Outlook, CloudFlare Hosting, Microsoft Azure Hosting, DemandBase, Brightcove. This information is useful for sales teams, recruiters, and technology vendors.
Is Gunnar Siebert open to recruiting or new opportunities?
CTO Rank does not track open-to-work status. The best approach is to reach out directly to Gunnar Siebert using the verified contact information available to Pro members. When recruiting a Head of M&A Cyber DACH, personalizing your outreach with specifics about the role and tech stack typically yields the best response rate.
Can I pitch or sell to Gunnar Siebert at Aon?
Gunnar Siebert is Head of M&A Cyber DACH at Aon. Head of Securitys like Gunnar Siebert typically evaluate vendors in Cloudflare DNS, Outlook, CloudFlare Hosting, and related categories. Use CTO Rank Pro to get verified email and approach directly.
How accurate is Gunnar Siebert's profile data?
CTO Rank verifies and refreshes profile data weekly. Gunnar Siebert's profile includes verified contact details, company information, and technology stack data sourced from multiple public and proprietary sources.
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