Vasileios Chatzigiannakis is a lawyer before the Supreme Court (Areios Pagos) with twenty years of experience, and a member and managing partner of “Evangelos Chatzigiannakis Law Firm.” He has expertise in public procurement law, local government law, environmental law, and public law in general. He has collaborated with major public bodies such as the Ministries of Environment and Justice, EYDAP, ADMIE, Piraeus Port Authority, EDSNA, ELTA Courier, the European Investment Bank, numerous municipalities and regions and their legal entities (Municipal Water and Sewerage Companies, Solid Waste Management Bodies, Regional Development Funds), as well as private sector entities. He has served as a member of Working Groups assisting the work of the Hellenic Single Public Procurement Authority (E.A.A.DI.SY.) in drafting standard tender documents (2020–2021), and as a member of the legislative working group for the amendment of public procurement legislation (2018–2019). He has appeared before Supreme Courts in significant cases in the field of public procurement, such as the case before the Plenary of the Council of State concerning Article 372 of Law 4412/2016, as well as in most cases heard under the model trial procedure, which have shaped important case law in this specialized field (indicatively: CoS 770/2021 7-member panel, 2221/2023 7-member panel, 211/2024 Plenary, 289/2024 7-member panel, 1147/2024 7-member panel, 1271/2024 7-member panel, 1412/2024 7-member panel, 49/2025 7-member panel, 880/2025 7-member panel, 1097/2025 Plenary). He is a lecturer in seminars and a speaker at conferences on public procurement. He has authored the books “Legality Controls in Public Procurement” (Nomiki Bibliothiki, 2023) and “Economic Operators – The Right to Participate in Public Procurement” (Nomiki Bibliothiki, 2025). He frequently publishes articles in legal journals such as Theory and Practice of Administrative Law, Review of Public and Administrative Law, Case Law on Public Works and Environment, and on the website nomarchia.gr.