For 18 years he had worked at the Ministry of Interior Affairs and after his departure from the police force in 2001, he got employed at a private company. In 2007 he returned into the public service as the manager of the cultural club in Cupcini, a town in Edinet District.

In late 2015, Nicolai Melnic joined the Moldovan Socialists Party (PSRM), and several months later he was elected a deputy mayor of Cupcini. Simultaneously he took over the leadership of the PSRM branch in Edinet District.

During the February 2019 parliamentary elections, he was a PSRM candidate in Constituency #3 Edinet and was defeated by Democratic Party candidate Oleg Sirbu by a difference of 1,000 votes, who won the counting.

During the October 2019 local elections, Mr. Melnic was PSRM’s number one candidate for election in the Edinet district council. The party grabbed most of the seats – 13 out of 33. In November 2019, Nicolai Melnic was elected as the chairman of Edinet District.