Sesks graduated from the Latvian Academy of Agriculture in Jelgava with a degree in mechanical engineering.
He improved his knowledge of entrepreneurship in Germany within a cooperation project with the North Rhine-Westphalia Chamber of Commerce.
[2] In 1997, Sesks was elected the Chairman of the Liepāja City Council (Mayor) and re-elected to this position in 2001 and 2005.
At the end of 2004, he established the Liepāja Party which has a cooperation agreement with the Union of Greens and Farmers.
He stepped down as mayor in November 2018, taking up a newly established vice-mayoral post.