Kaminer came out of high school as an All-American by Louisville Slugger after posting a 1.16 ERA career ERA with 190 strikeouts, which led him to commit to the Division I University of Miami. However, before his freshman season began, he transferred to Florida Southwestern State, making eight appearances with a 6.00 ERA. The southpaw then spent his sophomore year at Wallace Community College-Dothan, where he posted a 5.12 ERA in 65 innings, allowing just nine walks all year with 68 strikeouts. Kaminer’s command of the strike zone allowed him to transfer to Division I Louisiana State University, where he spent the 2020 and 2021 seasons. In 2020, Kaminer appeared in seven games, while posting a 2.84 ERA in 12.2 innings with five walks and 12 strikeouts. In 2021, he pitched in seven games as a reliever, posting no decisions and a 10.38 ERA in 4.1 innings. Kaminer transferred to Division I Georgia State for the 2022 season as a graduate student. While at GSU, Kaminer was a weekend starting pitcher who went 1-1 with a 3.74 ERA in 12 appearances as he collected 42 strikeouts in 43.1 innings. After college, Kaminer spent the summer of 2022 in the MLB Draft League with the Williamsport Crosscutters as he played in 10 games, delivering a 3.75 ERA, while striking out 27 batters. Kaminer made his way to the Pioneer League with the Northern Colorado Owlz, where he spent the 2023 and 2024 seasons. In 2023, he was mainly a starter, playing in 15 games while starting nine as he pitched 50 innings and posted a 9.18 ERA. He returned to Northern Colorado in 2024 but this time as a reliever, as he made 23 appearances while starting just one. He pitched in 30 innings as he posted an 8.70 ERA while striking out 24.