That post claims, "The aim of this post is to prove that from 1917-1990, there was not a single point at which the Communist Party of the Soviet Union or it’s leaders engaged in antisemitism." That is an incorrect statement. I don't know enough about Soviet history to provide a point-by-point breakdown of Soviet anti-Semitism, but I know someone who specializes in Jewish history, so I will consult with them then post a follow-up comment with more details. However, I can point to at least one example of anti-Semitism in the Soviet leadership, namely the Doctors' Plot, in which Stalin targeted Jewish doctors through imprisonment and an anti-Semitic media campaign out of a false belief they were trying to assassinate Soviet officials through intentional malpractice. The linked post brushes off accusations of the Doctors' Plot being anti-Semitic using the work of Grover Furr. While I may not be a specialist in Soviet history, I do know enough about Soviet historiography to know that Furr is a pretty thoroughly discredited Stalin apologist who has been discussed more than once on AskHistorians (links below on posts about Furr lack of credibility). Furthermore, the post uses, among other sources, communist propaganda opposed to anti-Semitism as evidence that there wasn't any anti-Semitism in the history of the leadership of the Soviet Union. While there can certainly be relatively objective analysis of socialist figures by socialist historians, I would hardly consider communist propaganda as an accurate source to use to prove the point they're trying to make. It appears me that they're working backward from their conclusion. Regardless, as I said, I will follow up with more details.
Links on Grover Furr, with main comments by /u/kieslowskifan, /u/fragmentedmachine, and /u/International_KB: