companies

Cosine

London-born YC startup behind Genie, an autonomous coding agent, now building UK sovereign frontier models for regulated industries.

Cosine was founded in London in 2022 by Alistair Pullen, Yang Li, and Sam Stenner. Pullen had been shipping AI products since his teens, and Li had previously scaled the bike-share company Mobike to 220 million riders before its acquisition; together they set out to build what they call a fully agentic software engineer rather than another autocomplete layer. The company went through Y Combinator and has raised roughly $8 million in seed funding from investors including Lakestar, SOMA Capital, and Gaingels. Cosine's flagship product, Genie, reads a codebase, plans a fix or feature, writes and tests the change, and opens a pull request from a ticket assigned in GitHub, Jira, Linear, or Slack, working asynchronously across many tickets at once rather than one chat session at a time. The company has reported leading scores on SWE-Bench among independently evaluated coding models. In 2026, Cosine became a cornerstone of the UK's sovereign AI push, recruiting BAE Systems, HSBC, Lloyds, NatWest, LSEG, PwC, and Thales as partners and securing 500,000 GPU hours on the Isambard-AI supercomputer to help train Lumen, a UK-hosted frontier model family aimed at customers who cannot send code or data to US-based model providers.

Founded

2022

Headquarters

London, United Kingdom

Sector

lab