Proximal builds infrastructure that enables AI to improve from real-world experience. In the past year, we have grown to more than $200M in annualized revenue helping frontier labs and enterprises improve coding agents. Now, we are expanding beyond software engineering. Recent progress in mathematics demonstrates what happens when models are trained in domains with massive amounts of public data and easy verifiability, making it easy to find weaknesses, generate training tasks, and iterate quickly. We build infrastructure that enables this feedback loop in other domains: we are excited about a world in which AI systems design targeted drugs, accelerate chip design, and rewrite legacy software that still runs hospitals, power grids, governments, and other critical infrastructure. Since starting, we have assembled a small team of researchers and engineers and built world-class infrastructure for post-training and synthetic data research to overcome the challenges of scaling manual data curation. Our team comes from Cursor, Google DeepMind, Meta Superintelligence, Prime Intellect, Citadel, and Jane Street. More than half are former founders. We’re fortunate to be backed by investors who share that vision, including @generalcatalyst who led our $15M Seed Round at a $300M valuation, as well as @chemistry, @svangel, @dvlamoen and individuals like @LiamFedus, @kevinweil, and @bernhardsson

Real life, baby

In September, we published the TORCS Racing Bot task as part of FrontierSWE Agents get 20h to build a bot that drives in a racing simulator as fast as possible, using only visual inputs. We are sharing a more detailed analysis and interesting findings from models' attempts

We are excited to announce that Deno is joining Cloudflare! deno.com/blog/cloudflare

At Proximal, we believe that building our own research infrastructure is crucial to design the highest-quality training data Today, we are sharing more information about our internal post-training stack

new post: collecting favours sunilpai.dev/posts/collectin… a post on the idea of "reputation". tried writing it a few times as an abstract thing and I hated it, so instead I just wrote about my dad.

1,049,817 open-source code reviews in September, a new monthly record! That's 2.49x April's volume and up 14.4% from August. "Not using it today would be like racing Formula One without a seatbelt or helmet." – @tannerlinsley, creator of TanStack

Introducing Claude Haiku 5.5: the cheapest, fastest, and most capable small model we’ve ever released. On average, it costs around 75% less to run than Claude Haiku 4.5.