Developer tools

Cosine

Website
Founded 2022Origin source ↗Checked 2026-09-15

Overview

Cosine is a fully agentic SWE that allows you to instantly work on every single ticket at once, asynchronously.

Company description As recorded 2026-11-08

Founders & team

Previously Buildt

Company history As recorded 2026-11-08

Alistair Pullen

Founder

Full-stack Software Engineer with 15 years experience with deep applied knowledge of LLMs and Embeddings. Currently building an AI dev tool. Experienced an exit with Fancy (YC S20, acq. GoPuff).

Founder profile As recorded 2026-09-15

Yang Li

Founder

1 IPO, 2 Acquisitions, 3 Unicorns. Ex VP of Europe for Digital Currency Group's consumer arm, Luno. Launched Ziglu (acquired by Robinhood) and scaled to 100,000 customers in the first year. Previously Commercial Director for Mobike (acquired by Meituan) growing it to 220M MAUs until the $55B IPO. Yang is one of the 2021 Forbes 30 under 30 cohort.

Founder profile As recorded 2026-09-15
12team members reported
Source-reported As recorded 2026-09-15

Founded 2022 · Source

News & product activity

Sources & observations

Y Combinator

Profile depthenriched profile
Website observationwebsite reachable
Last website check2026-11-11
Location · source statedLondon, England, United Kingdom
Pricing evidenceA pricing page was detected
Maturity: Not assessed · 4 of 6 areas documented

Source-based assessment · automated evidence rules

The homepage contains prelaunch or closure language; availability needs review.

Maturity is an evidence-based assessment, not a success rating. It may understate the current stage where evidence is limited. Coverage records documented areas, not a complete or independently audited company history.

Stage definitions
independent websitesource corroborationreachable websitedescriptive evidenceclassified market and modelsourced peoplesourced founding yearpricing page observeddocumentation observedrecent publishing observed