The register
The register lists ESG Book in London as a licensed sponsor on Global Business Mobility: Senior or Specialist Worker and Skilled Worker, 2 routes in all, and has done since at least 2026. Rating on the current register: Worker (A rating).
At Companies House the business is Esg Book (company number FC035689), a overseas company incorporated in 2018, 8 years ago. Registered office: C/O K- 1 Business Club Junghof, Neue Rothofstrasse 13-19, Frankfurt Am Main, 60313. It has traded under other names before, including Arabesque S-ray Gmbh, UK Branch.
A licence says an organisation may sponsor; it does not say it is hiring today. The way to find out is the same as for any employer: the careers page, the job boards, and a direct approach with a UK-style CV that says early that sponsorship would be needed.