He started in 1996 as a registrar at the Chisinau Municipal Tribunal. One year later he was promoted to adviser of the chairman of the Moldovan Court of Appeal, Nicolae Timofti, the future president of Moldova. In 2001, Oleg Sternioala advanced to the post of judge at the Ciocana District Court in the capital and five years later he became its deputy chairman. In 2008 he was appointed as chairman of the Buiucani District Court.

In 2014, Parliament Speaker Igor Corman signed a decision that landed Oleg Sternioala to the seat of judge in the Supreme Court of Justice (CSJ); he will work there until the age of retirement: 65. In 2017 the new speaker, Andrian Candu, signed another decision, which gave the judge an administrative job in CSJ - deputy chairman of the panel for civilian, commercial, and administrative lawsuits, for a four-year term.

On 4 November 2019, the acting prosecutor-general, Dumitru Robu, obtained the consent of the High Council of Magistrates (CSM) to lift the immunity and prosecute Oleg Sternioala over corruption suspicions. The same day anticorruption prosecutors and police searched the home and office of Mr. Sternioala and held him in custody for 72 hours.

A press release issued by the Prosecutor-General’s Office said that Oleg Sternioala was suspected of money laundering in large proportions based on journalist investigations that revealed the size and value of the judge’s properties. A scrutiny of his financial records unearthed evidence that his family had earned around 7 million lei but spent some 13.8 million lei. Prosecutors were seeking to demonstrate that the difference had been gathered illegally.

Oleg Sternioala was quick to file for resignation, which CSM accepted on 13 December 2019.