Tatiana Vieru’s career in the judiciary system began in 1971, as a registrar at the Soroca City Court. In 1982 she earns an appointment as a judge in the Botanica Districtual Court in the capital and in 1996 Mrs. Vieru got promoted to the Chisinau Court of Appeal.

Mrs. Vieru entered the Supreme Court of Justice in 2003 and in 2016 she was named its deputy chairwoman, who was also in charge with leadership in the board for civil, commercial and administrative disputes for four years. On 24 September 2019, Tatiana Vieru resigned from the post and quit the judiciary system on 5 November 2019.

In 2012, the high Council of Magistrates honored her with the honorary title “Dean of Judiciary Authority” and awarded her a Honorary Diploma in 2016.