The register
The register lists Rattling Stick LTD. in London as a licensed sponsor on Creative Worker, an entry that goes back to at least 2026. Rating on the current register: Temporary Worker (A rating).
At Companies House the business is Rattling Stick Limited (company number 05229504), a private limited company incorporated in 2004, 22 years ago. Registered office: 6th Floor Charlotte Building, 17 Gresse Street, London, W1T 1QL, W1T 1QL. Its filed activity puts it in it, software and media. It has traded under other names before, including Kleinman Productions Limited.
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.