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Co-Founder and CEO

Michael Shieh

Michael brings more than 20 years of leadership in product and engineering in the security industry.

Prior to Mammoth Cyber, Michael was co-founder and CTO of vArmour where he led the launch of the first micro-segmentation solution for hybrid cloud applications. His prior experience also includes various engineering leadership positions at Juniper, Netscreen, and Lucent Technology.

Michael holds a Bachelor of Science in Mechanical Engineering from National Taiwan University and a Masters of Science in Mechanical Engineering from University of Missouri, Columbia. In his spare time Michael enjoys hiking, biking and listening to music.

Co-Founder and CTO

Yonghui Cheng

Yonghui Cheng has 20 years of experience in the Security industry. He has built engineering organizations from the ground up and delivered several enterprise and carrier grade security solutions.

Yonghui was a Fellow at Palo Alto Networks where he worked on diverse solutions ranging from delivering highly scalable public and private cloud solutions to building a wide range of custom embedded systems. He has also had engineering leadership and developer roles in Juniper Networks and NetScreen.

Yonghui holds both a Bachelor’s and a Master’s degree in Computer Science from Tsinghua University and an MBA from the Wharton School. Outside of work, Yonghui enjoys spending time with family and friends as well as exploring his love for the outdoors while skiing and hiking.

Vice-President, Worldwide Sales

David Weier

David comes to Mammoth with a 20 plus year track record of surpassing revenue targets at technology companies ranging from early stage startups to large enterprises.

Most recently, he served as a Vice President of Sales at DeepSee and SignalFx. David has also held senior sales executive positions at companies including E8 Security (acquired by VMware), Solera Networks (acquired by Blue Coat Systems), SilverTail Systems (acquired by RSA), Opsware (acquired by Hewlett- Packard) and PTC, among others.

David has a BA in English and Political Science from St. Olaf College. He is an avid reader and runner who loves spending time with family.


Peter Lunk

Peter Lunk has over 20 years in the cybersecurity and technology industries. Most recently, he served as CMO for CloudSphere, a cyber asset management and security company. Prior to CloudSphere, Peter served as the Vice President of Marketing for startups Menlo Security and Wurldtech (Acquired by GE) and led Product Marketing for Juniper Networks’ $1B Security Business Unit.

Peter holds a Bachelor of Science in Electrical Engineering and Computer Science from UC Berkeley and a Master’s in Electrical Engineering from Santa Clara University. Peter is an avid cyclist, and outside of work you will most likely find him riding and racing mountain bikes.