In 2017, Schwartz signed with the defending champions BC Oostende. In the 2020 offseason, Schwartz extended his contract with Oostende until 2023.[2] In the 2020–21 season, Schwartz had a breakout season in which he averaged 11.4 points per game. In March, he won his third Belgian Cup title and was named the Cup Final MVP, after he added 11 points in the final.[3] His season earned him the Belgian Player of the Year.[4] Later, he won his fourth Belgian championship with Oostende and was named the PBL Finals MVP.[5] In the finals series against Mons-Hainaut, he averaged 11.5 points, 4.5 rebounds and 3 assists per game.[6]