YC active company list audit

Cosine

Cosine: Fully Agentic SWE. Headquartered in London, England, United Kingdom. Current operating status: active.

Oomira checked this YC company record against source evidence and keeps the current facts, observed dates, and provenance visible before the interactive app loads.

17 facts4 sources1 superseded claims

What is Cosine?

Cosine: Fully Agentic SWE. Headquartered in London, England, United Kingdom. Current operating status: active.

What is true now?

Cosine is currently marked active, in B2B, based in London, England, United Kingdom, with hiring marked yes.

What did the audit learn?

Oomira found 1 change for Cosine: external name. The old value, newer value, observation date, and source trail are preserved together.

When was this observed?

The frozen capsule includes observations from 2026. Dates stay attached to the facts instead of being flattened into a timeless profile.

What evidence supports it?

yc-oss record id 27839: field "one_liner"
yc-oss record id 27839: field "long_description"
yc-oss record id 27839: field "website" = "http://www.cosine.sh"
YC directory: isHiring = true
HQ: London, England, United Kingdom (YC directory)

Why Oomira has this page

This page exposes the company answer, changes, dates, and sources as HTML so people and crawlers can read the audit without operating the app.

What changed in the audit

external name

Buildt -> Cosine
2026-06-12 · yc-oss record id 27839: field "former_names" includes "Buildt"

Summary: Fully Agentic SWE
Description: Cosine is a fully agentic SWE that allows you to instantly work on every single ticket at once, asynchronously.
Website: https://www.cosine.sh
Hiring: yes
Headquarters: London, England, United Kingdom
Operating status: active
Industry: B2B

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Cosine in the YC active list audit - Oomira