Dan Mackin


B.S., Electrical and Computer Engineering (ECE) (University of Colorado Boulder); CISSP, GSNA, PCI QSA, RHCSA

Dan Mackin is Co-Founder and Co-CEO of Rule4. Dan is well-known in the industry for applying opensource and cybersecurity at enterprise scale. His previous roles include COO of an IT infrastructure, security, and opensource consulting services provider, and Senior Vice President of Professional Services for a nationwide datacenter operator.

Dan specializes in client engagements involving large-scale Linux server environments and compliance efforts with standards such as the Payment Card Industry Data Security Standard (PCI DSS), the Health Insurance Portability and Accountability Act (HIPAA), and 800-171/CMMC. Dan is particularly passionate about cloud security and takes a cloud-agnostic approach, securing environments in AWS, Azure, and GCP.

Dan is a co-author of the “Unix and Linux System Administration Handbook,” currently in its fifth edition, and he curates the Boulder Linux Users Group (BLUG) meetup. He also firmly believes in the importance of giving back to the community, and volunteers at and serves on the board for Sister Carmen Community Center.

As a passionate backcountry skier and advocate for the Colorado wilderness, Dan has championed and consulted on multiple projects for the Colorado Avalanche Information Center, donating his time to dig into their systems and help secure the technology used to provide real-time avalanche forecasts and advisories for resorts, mountain roads and highways, and backcountry recreation enthusiasts. This partnership is saving lives and increasing access to the amazing Colorado high country.

Away from the office, Dan likes to sink his teeth into new creative pursuits, whether it’s welding, woodworking, or applying Linux and other opensource technologies to automation, monitoring, and metrics collection projects. He loves cheering on the Colorado Buffaloes and Dallas Cowboys, skiing, camping, sailing, backcountry touring, four-wheeling, and spending time with his wife and dog, Daisy.

Fox Trivia

My favorite adventure:

Winter hut trips in the Colorado backcountry!

Favorite podcast:

It's a tie between Freakonomics Radio and Hidden Brain.

Favorite piece of outdoor gear:

Icelantic Nomad RKR 181s

Spirit animal:


Dream job in an alternate universe:

Ranching buffaloes!

Quote I live by:

A smooth sea never made a skilled sailor.