diff --git a/.circleci/config.yml b/.circleci/config.yml
index b616f3bde93..95a2baaa8fa 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -1658,65 +1658,14 @@ workflows:
           cu_version: cpu
           name: unittest_windows_cpu_py3.7
           python_version: '3.7'
-      - unittest_windows_cpu:
-          cu_version: cpu
-          name: unittest_windows_cpu_py3.8
-          python_version: '3.8'
-      - unittest_windows_cpu:
-          cu_version: cpu
-          name: unittest_windows_cpu_py3.9
-          python_version: '3.9'
-      - unittest_windows_cpu:
-          cu_version: cpu
-          name: unittest_windows_cpu_py3.10
-          python_version: '3.10'
       - unittest_windows_gpu:
           cu_version: cu102
-          filters:
-            branches:
-              only:
-              - main
-              - nightly
           name: unittest_windows_gpu_py3.7
           python_version: '3.7'
-      - unittest_windows_gpu:
-          cu_version: cu102
-          name: unittest_windows_gpu_py3.8
-          python_version: '3.8'
-      - unittest_windows_gpu:
-          cu_version: cu102
-          filters:
-            branches:
-              only:
-              - main
-              - nightly
-          name: unittest_windows_gpu_py3.9
-          python_version: '3.9'
-      - unittest_windows_gpu:
-          cu_version: cu102
-          filters:
-            branches:
-              only:
-              - main
-              - nightly
-          name: unittest_windows_gpu_py3.10
-          python_version: '3.10'
       - unittest_macos_cpu:
           cu_version: cpu
           name: unittest_macos_cpu_py3.7
           python_version: '3.7'
-      - unittest_macos_cpu:
-          cu_version: cpu
-          name: unittest_macos_cpu_py3.8
-          python_version: '3.8'
-      - unittest_macos_cpu:
-          cu_version: cpu
-          name: unittest_macos_cpu_py3.9
-          python_version: '3.9'
-      - unittest_macos_cpu:
-          cu_version: cpu
-          name: unittest_macos_cpu_py3.10
-          python_version: '3.10'
 
   cmake:
     jobs:
diff --git a/.circleci/regenerate.py b/.circleci/regenerate.py
index b860d71f14d..8f674ec0630 100755
--- a/.circleci/regenerate.py
+++ b/.circleci/regenerate.py
@@ -236,20 +236,28 @@ def indent(indentation, data_list):
     return ("\n" + " " * indentation).join(yaml.dump(data_list, default_flow_style=False).splitlines())
 
 
+def unittest_python_versions(os):
+    return {
+        "windows": PYTHON_VERSIONS[:1],
+        "macos": PYTHON_VERSIONS[:1],
+        "linux": PYTHON_VERSIONS,
+    }.get(os)
+
+
 def unittest_workflows(indentation=6):
     jobs = []
     for os_type in ["linux", "windows", "macos"]:
         for device_type in ["cpu", "gpu"]:
             if os_type == "macos" and device_type == "gpu":
                 continue
-            for i, python_version in enumerate(PYTHON_VERSIONS):
+            for i, python_version in enumerate(unittest_python_versions(os_type)):
                 job = {
                     "name": f"unittest_{os_type}_{device_type}_py{python_version}",
                     "python_version": python_version,
                 }
 
                 if device_type == "gpu":
-                    if python_version != "3.8":
+                    if os_type != "windows" and python_version != "3.8":
                         job["filters"] = gen_filter_branch_tree("main", "nightly")
                     job["cu_version"] = "cu102"
                 else: