Censys

Censys turned a University of Michigan research project into one of the most important data platforms in cybersecurity. The company maintains a continuous scan of the entire public internet, capturing the state of every exposed service on every IP address on Earth, then makes that data searchable for defenders, researchers, and threat intelligence teams. If you work in security operations at a Fortune 500 or a three-letter agency, you almost certainly use Censys.

The technical work is substantial. Running a global internet scan responsibly, at scale, with high fidelity, across IPv4 and a meaningful slice of IPv6, is an infrastructure problem that very few companies attempt. Censys has spent close to a decade hardening its pipeline, and the data quality is the moat. The company's attack surface management product takes that same scanning engine and flips it into an internal view for enterprise security teams who need to know what their own footprint actually looks like from the outside.

Censys grew out of research by Zakir Durumeric and collaborators at U-M, and it has raised more than 100 million dollars from Decibel, GV, Greylock, and others. The company is one of several serious A2 cybersecurity exits and scale-ups in the lineage that starts with Arbor Networks and runs through Duo Security. That lineage is not an accident. U-M's computer security research group has been top-ranked for years, and Ann Arbor has become a natural launch point for category-defining security companies.

The downtown Ann Arbor office keeps engineers close to the research that still produces Censys's next generation of techniques. The walk to Zingerman's is two blocks. The walk to a house in Kerrytown is ten minutes. The tax and cost-of-living swing from Palo Alto or Austin is severe in the best way. This is a place where security engineers can do research-grade work and still own a house before their second vesting cliff.