Kernel

Kernel is developing non-invasive neuroimaging technology for research and enterprise applications, founded by Braintree co-founder Bryan Johnson. The company's Kernel Flow system uses time-domain fNIRS to measure hemodynamic brain activity at high temporal resolution across a full-head array. Johnson self-funded the company with $100M in 2016, followed by a $53M Series C in 2020 led by General Catalyst with Khosla Ventures. Kernel targets pharmaceutical companies needing objective neural biomarkers for clinical trials, longevity clinics, and enterprise brain health monitoring. The company launched Kernel Trackers as initial wellness products for longevity clinics in 2025.