Yiannos has been practicing law since 1990 and his main focus of his law firm is on litigation, corporate and commercial law, mergers and acquisitions, IP and technology, medical law, real estate, ADR.

He is a member of the Cyprus Bar Association, the Law Society in the UK as a European Registered Lawyer and President of the Cyprus Chapter of the European Court of Arbitration and Mediation for commercial disputes (CEAM). He is also the President of GLAWBUS Global Law and Business Organisation for lawyers and professionals. He is also listed as a legal professional representative before the European Patent Office, for the purpose of representing clients before the EPO.

He is a co-founder of the business accelerator KV Kinisis Ventures Limited, which aims at scaling up innovative and technology companies to the US market. He is nominated advisor for the Emerging Companies Market (the ECM) of the Cyprus Stock Exchange and has been appointed to the CY-Biobank Independent Bioethics Advisory Board as part of the Centre of Excellence in Biobanking and Biomedical Research, co-founded by the European Commission, the Government of Cyprus and the University of Cyprus.

Yiannos graduated from West London University (LL.B. Hons.) in 1989 and Inns of Court School of Law, Honourable Society of Gray's Inn, London (Barrister-at-Law) in 1990. Apart from becoming a Barrister, he has previously worked in a reputable solicitor's firm in London, as well as worked as a visiting attorney at Corboy & Demetrio in Chicago and Baker & Hostetler in Washington, D.C. in the US.