Hard Tech Startups funded by Y Combinator (YC) in the San Francisco Bay Area 2025

We're building a mobile and wearable digital wallet that makes interacting with payments, identity, and authentication seamless, fun, and empowering. Acquired by OURA in 2023

Holy Grail removes carbon dioxide from the atmosphere to contribute to the long-term sustainability of humans and other species on Earth

Observant is an iPhone-based driver monitoring system for commercial fleets. It uses machine learning + iPhone's depth sensors to detect unsafe driver behavior, prevent accidents, and save lives.

Teleo converts heavy equipment, like dozers, trucks, and loaders, into supervised autonomous robots. This enables a single operator to remotely operate multiple machines while sitting at a remote control center, unlocking productivity gains for the General Contractor.

Auricle is a medical device company building a breakthrough neurostimulation implant to restore hearing in millions of patients who no longer benefit from hearing aids, get less than 60% on a word recognition test, but aren't prepared to make the jump to a cochlear implant. Our approach preserves remaining natural hearing through a reversible and less invasive surgery, addressing the key concerns that hold most patients back from getting a cochlear implant (currently the only treatment option for these patients). The company spun out of Stanford Biodesign having completed two acute human clinical studies demonstrating the approach will work. The team is now focused on developing their full implant system for their first clinical trial. Auricle addresses a currently unserved profile of hearing loss that affects a growing population of 3.5 million patients in the US and represents an immediately accessible $1.2B market opportunity with existing reimbursement.

Ultralight is a GPU-accelerated toolkit to embed modern HTML in games and native apps. Available for C and C++ on Windows, macOS, Linux, Xbox, PlayStation, ARM64 devices, and more. Developed in collaboration with leading game studios, built GPU-first on a new, lightweight fork of WebKit.

We bring Tesla autonomous manufacturing to every automaker and other producers. At Tesla, we were the core autonomous factory team and we’re now building the smart cameras and robotic guidance tools that provided the main advantages at Tesla

Integrated Reasoning builds efficient computer processors that are tailored to the memory access patterns of Karp's 21 NP-complete problems. We’re making it 100x - 10,000x faster to perform computations like scheduling airline pilots or optimizing packing layouts for shipping containers.

We use the printing methods used for newspapers, packaging, posters, and other graphic media to make beautiful, emissive electronic displays with high-end OLED technology aimed at low-cost applications. Our displays are paper-thin, flexible, and can be easily custom printed in a variety of shapes and sizes, allowing hardware designers to use displays and indicators on curved surfaces and in new ways.

We help truckers cut delivery times, increasing productivity and adding much needed capacity to the freight industry. We do this by building autonomy software that tag-teams with human drivers. Conventional trucks drive ~120K miles/ year. Trucks with our tech can hit more than 190K miles/ year.

AirMyne is building machines to capture & remove carbon dioxide from ambient atmospheric air so it can be utilized or sequestered downstream. Our team is based in Berkeley, CA.

We build automated robots for concrete floor construction. One person with our robots does the work of 6 construction workers.