After postdoctoral positions at the Max Planck Institute for Dynamics and Self-Organization, Göttingen he became associate professor in the Department of Engineering Sciences and Applied Mathematics at Northwestern University in 2008.

Brockmann pioneered the scientific use of mass data collected in online games in a 2006 study in which he and his colleagues analyzed the geographic circulation of millions of dollar-bills registered at the online bill tracking website Where's George?

In a 2013 study Brockmann and his colleague Dirk Helbing showed that complex global contagion phenomena can be mapped onto simple propagating wave patterns using the theoretical concept of effective distance.

[9] This method was employed for import risk estimates during the Ebola virus epidemic in West Africa in 2014.

Brockmann's research has been featured in an episode of the American crime drama television series Numbers.