diff --git a/.circleci/setup_env.sh b/.circleci/setup_env.sh
index c03a7ff4be8b3..c88250d6f48d2 100755
--- a/.circleci/setup_env.sh
+++ b/.circleci/setup_env.sh
@@ -98,9 +98,10 @@ if [ "$(conda list -f qt --json)" != [] ]; then
 fi
 
 echo "Build extensions"
-python setup.py build_ext -q -j3
+cmake .
+cmake --build . --config Release --parallel
 
 echo "Install pandas"
-python -m pip install --no-build-isolation --no-use-pep517 -e .
+python -m pip install --no-build-isolation -e .
 
 echo "done"
diff --git a/.github/actions/build_pandas/action.yml b/.github/actions/build_pandas/action.yml
index 23bb988ef4d73..4d2ff17b4541b 100644
--- a/.github/actions/build_pandas/action.yml
+++ b/.github/actions/build_pandas/action.yml
@@ -12,8 +12,9 @@ runs:
 
     - name: Build Pandas
       run: |
-        python setup.py build_ext -j $N_JOBS
-        python -m pip install -e . --no-build-isolation --no-use-pep517 --no-index
+        cmake .
+        cmake --build . --config Release --parallel
+        python -m pip install -e . --no-build-isolation  --no-index
       shell: bash -el {0}
       env:
         # Cannot use parallel compilation on Windows, see https://github.com/pandas-dev/pandas/issues/30873
diff --git a/.github/workflows/32-bit-linux.yml b/.github/workflows/32-bit-linux.yml
index 67e99b4486a12..25eac102ca599 100644
--- a/.github/workflows/32-bit-linux.yml
+++ b/.github/workflows/32-bit-linux.yml
@@ -38,10 +38,11 @@ jobs:
           /opt/python/cp38-cp38/bin/python -m venv ~/virtualenvs/pandas-dev && \
           . ~/virtualenvs/pandas-dev/bin/activate && \
           python -m pip install --no-deps -U pip wheel 'setuptools<60.0.0' && \
-          pip install cython numpy python-dateutil pytz pytest pytest-xdist pytest-asyncio>=0.17 hypothesis && \
-          python setup.py build_ext -q -j1 && \
-          python -m pip install --no-build-isolation --no-use-pep517 -e . && \
-          python -m pip list && \
+          pip install cmake cython numpy python-dateutil pytz pytest pytest-xdist pytest-asyncio>=0.17 hypothesis && \
+          cmake . && \
+          cmake --build . --parallel && \
+          python -m pip install --no-build-isolation -e . && \
+	  python -m pip list && \
           export PANDAS_CI=1 && \
           pytest -m 'not slow and not network and not clipboard and not single_cpu' pandas --junitxml=test-data.xml"
 
diff --git a/.gitignore b/.gitignore
index 07b1f056d511b..b0782dc31b09b 100644
--- a/.gitignore
+++ b/.gitignore
@@ -37,6 +37,10 @@
 *.so
 .build_cache_dir
 MANIFEST
+Makefile
+CMakeCache.txt
+CMakeFiles/
+cmake_install.cmake
 
 # Python files #
 ################
diff --git a/CMakeLists.txt b/CMakeLists.txt
new file mode 100644
index 0000000000000..fcf450e557e39
--- /dev/null
+++ b/CMakeLists.txt
@@ -0,0 +1,29 @@
+cmake_minimum_required(VERSION 3.18)
+
+set(CMAKE_OSX_DEPLOYMENT_TARGET "10.9")
+set(CMAKE_C_STANDARD 99)
+set(CMAKE_C_STANDARD_REQUIRED True)
+set(CMAKE_CXX_STANDARD 11)
+set(CMAKE_CXX_STANDARD_REQUIRED True)
+
+project(pandas)
+
+if(WIN32)
+  if(NOT CMAKE_BUILD_TYPE)
+    set(CMAKE_BUILD_TYPE
+        Release
+        CACHE STRING "Build type" FORCE)
+  endif()
+  find_package(Python3 REQUIRED COMPONENTS Interpreter Development NumPy)
+  set(CMAKE_LIBRARY_OUTPUT_DIRECTORY_RELEASE "")
+  link_directories(${Python3_LIBRARY_DIRS})
+else()
+  # we only choose Development.Module to support virtual environments where
+  # libpython may not be available see
+  # https://github.com/pypa/manylinux/issues/484
+  find_package(Python3 REQUIRED COMPONENTS Interpreter Development.Module NumPy)
+endif()
+
+add_compile_definitions(NPY_NO_DEPRECATED_API=0)
+add_subdirectory("pandas/_libs")
+add_subdirectory("pandas/io/sas")
diff --git a/Dockerfile b/Dockerfile
index 650ba14271092..8fd0bc0b927f2 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -49,5 +49,6 @@ RUN . /opt/conda/etc/profile.d/conda.sh \
     && conda activate base \
     && cd "$pandas_home" \
     && export \
-    && python setup.py build_ext -j 4 \
+    && cmake . \
+    && cmake --build . --parallel \
     && python -m pip install --no-build-isolation -e .
diff --git a/MANIFEST.in b/MANIFEST.in
index d2b1b8cb887bc..cd13a469043b2 100644
--- a/MANIFEST.in
+++ b/MANIFEST.in
@@ -1,5 +1,6 @@
 include RELEASE.md
 include versioneer.py
+include CMakeLists.txt
 
 graft doc
 prune doc/build
@@ -7,6 +8,7 @@ prune doc/build
 graft LICENSES
 
 graft pandas
+graft build_support
 
 global-exclude *.bz2
 global-exclude *.csv
@@ -28,7 +30,6 @@ global-exclude *.odt
 global-exclude *.orc
 global-exclude *.sas7bdat
 global-exclude *.sav
-global-exclude *.so
 global-exclude *.xls
 global-exclude *.xlsb
 global-exclude *.xlsm
@@ -42,6 +43,9 @@ global-exclude *~
 global-exclude .DS_Store
 global-exclude .git*
 global-exclude \#*
+recursive-exclude **/CMakeFiles *
+global-exclude *.cmake
+global-exclude CMakeCache.txt
 
 global-exclude *.c
 global-exclude *.cpp
diff --git a/Makefile b/Makefile
deleted file mode 100644
index c0aa685ed47ac..0000000000000
--- a/Makefile
+++ /dev/null
@@ -1,30 +0,0 @@
-.PHONY : develop build clean clean_pyc doc lint-diff black test-scripts
-
-all: develop
-
-clean:
-	-python setup.py clean
-
-clean_pyc:
-	-find . -name '*.py[co]' -exec rm {} \;
-
-build: clean_pyc
-	python setup.py build_ext
-
-lint-diff:
-	git diff upstream/main --name-only -- "*.py" | xargs flake8
-
-black:
-	black .
-
-develop: build
-	python -m pip install --no-build-isolation -e .
-
-doc:
-	-rm -rf doc/build doc/source/generated
-	cd doc; \
-	python make.py clean; \
-	python make.py html
-
-test-scripts:
-	pytest scripts
diff --git a/build_support/build_backend.py b/build_support/build_backend.py
new file mode 100644
index 0000000000000..90fe28fb9b33a
--- /dev/null
+++ b/build_support/build_backend.py
@@ -0,0 +1,21 @@
+import pathlib
+import subprocess
+
+from setuptools import build_meta as _orig
+
+prepare_metadata_for_build_wheel = _orig.prepare_metadata_for_build_wheel
+build_sdist = _orig.build_sdist
+get_requires_for_build_wheel = _orig.get_requires_for_build_wheel
+get_requires_for_build_sdist = _orig.get_requires_for_build_sdist
+
+
+def build_wheel(wheel_directory, config_settings=None, metadata_directory=None):
+    filedir = pathlib.Path(__file__).resolve().parent.parent
+    subprocess.run(["cmake", "."], cwd=filedir, check=True)
+    subprocess.run(
+        ["cmake", "--build", ".", "--config", "Release", "--parallel"],
+        cwd=filedir,
+        check=True,
+    )
+
+    return _orig.build_wheel(wheel_directory, config_settings, metadata_directory)
diff --git a/doc/source/development/contributing_environment.rst b/doc/source/development/contributing_environment.rst
index c881770aa7584..32c9ea82f8ddf 100644
--- a/doc/source/development/contributing_environment.rst
+++ b/doc/source/development/contributing_environment.rst
@@ -42,7 +42,8 @@ Run Container::
     If you bind your local repo for the first time, you have to build the C extensions afterwards.
     Run the following command inside the container::
 
-        python setup.py build_ext -j 4
+        cmake .
+        cmake --build . --config Release --parallel
 
     You need to rebuild the C extensions anytime the Cython code in ``pandas/_libs`` changes.
     This most frequently occurs when changing or merging branches.
@@ -169,7 +170,8 @@ We'll now kick off a three-step process:
    source activate pandas-dev
 
    # Build and install pandas
-   python setup.py build_ext -j 4
+   cmake .
+   cmake --build . --config Release --parallel
    python -m pip install -e . --no-build-isolation --no-use-pep517
 
 At this point you should be able to import pandas from your locally built version::
@@ -216,7 +218,8 @@ You also need to have ``setuptools`` 51.0.0 or later to build pandas.
    python -m pip install -r requirements-dev.txt
 
    # Build and install pandas
-   python setup.py build_ext -j 4
+   cmake .
+   cmake --build . --config Release --parallel
    python -m pip install -e . --no-build-isolation --no-use-pep517
 
 **Unix**/**macOS with pyenv**
@@ -240,7 +243,8 @@ Consult the docs for setting up pyenv `here <https://github.com/pyenv/pyenv>`__.
    python -m pip install -r requirements-dev.txt
 
    # Build and install pandas
-   python setup.py build_ext -j 4
+   cmake .
+   cmake --build . --config Release --parallel
    python -m pip install -e . --no-build-isolation --no-use-pep517
 
 **Windows**
@@ -266,5 +270,6 @@ should already exist.
    python -m pip install -r requirements-dev.txt
 
    # Build and install pandas
-   python setup.py build_ext -j 4
+   cmake .
+   cmake --build . --config Release --parallel
    python -m pip install -e . --no-build-isolation --no-use-pep517
diff --git a/doc/source/development/debugging_extensions.rst b/doc/source/development/debugging_extensions.rst
index 7ba2091e18853..b2865f97e2613 100644
--- a/doc/source/development/debugging_extensions.rst
+++ b/doc/source/development/debugging_extensions.rst
@@ -8,11 +8,12 @@ Debugging C extensions
 
 Pandas uses select C extensions for high performance IO operations. In case you need to debug segfaults or general issues with those extensions, the following steps may be helpful.
 
-First, be sure to compile the extensions with the appropriate flags to generate debug symbols and remove optimizations. This can be achieved as follows:
+First, be sure to compile the extensions with the appropriate flags to generate debug symbols and remove optimizations. This can be achieved on Unix-like systems as follows:
 
 .. code-block:: sh
 
-   python setup.py build_ext --inplace -j4 --with-debugging-symbols
+   cmake . -DCMAKE_BUILD_TYPE=Debug
+   cmake --build . --parallel
 
 Using a debugger
 ================
diff --git a/environment.yml b/environment.yml
index f1472f453b935..5dc0dcc477dae 100644
--- a/environment.yml
+++ b/environment.yml
@@ -79,6 +79,7 @@ dependencies:
   - asv
 
   # The compiler packages are meta-packages and install the correct compiler (activation) packages on the respective platforms.
+  - cmake>=3.18.0
   - c-compiler
   - cxx-compiler
 
diff --git a/pandas/__init__.py b/pandas/__init__.py
index 5016bde000c3b..229aa77efdefe 100644
--- a/pandas/__init__.py
+++ b/pandas/__init__.py
@@ -28,7 +28,8 @@
     raise ImportError(
         f"C extension: {_module} not built. If you want to import "
         "pandas from the source directory, you may need to run "
-        "'python setup.py build_ext --force' to build the C extensions first."
+        "'cmake . && cmake --build . --config Release --parallel' "
+        "to build the C extensions first."
     ) from _err
 else:
     del _tslib, _lib, _hashtable
diff --git a/pandas/_libs/CMakeLists.txt b/pandas/_libs/CMakeLists.txt
new file mode 100644
index 0000000000000..3aa1e7a225476
--- /dev/null
+++ b/pandas/_libs/CMakeLists.txt
@@ -0,0 +1,142 @@
+add_custom_command(
+  OUTPUT algos_common_helper.pxi
+         algos_take_helper.pxi
+         hashtable_class_helper.pxi
+         hashtable_func_helper.pxi
+         index_class_helper.pxi
+         intervaltree.pxi
+         khash_for_primitive_helper.pxi
+         sparse_op_helper.pxi
+  COMMAND ${Python3_EXECUTABLE} generate_templates.py)
+
+add_custom_command(
+  OUTPUT algos.c
+  COMMAND ${Python3_EXECUTABLE} -m cython -3 algos.pyx
+  DEPENDS algos_common_helper.pxi algos_take_helper.pxi)
+python3_add_library(algos MODULE WITH_SOABI algos.c)
+target_include_directories(
+  algos PUBLIC ${Python3_INCLUDE_DIRS} ${Python3_NumPy_INCLUDE_DIRS} "src/klib")
+
+# There is a khash header file in src/klib and a cython generated one in _libs.
+# Depending on the build timing one of the other could get picked up, though
+# unclear why we need both? If we stick to the non-generated version we can
+# remove any DEPENDS khash.h
+add_custom_command(
+  OUTPUT khash.h
+  COMMAND ${Python3_EXECUTABLE} -m cython -3 khash.pxd
+  DEPENDS hkash_for_primitive_helper.pxi)
+
+add_custom_command(
+  OUTPUT hashtable.c
+  COMMAND ${Python3_EXECUTABLE} -m cython -3 hashtable.pyx
+  DEPENDS hashtable_class_helper.pxi hashtable_func_helper.pxi)
+
+python3_add_library(hashtable MODULE WITH_SOABI hashtable.c)
+target_include_directories(
+  hashtable PUBLIC ${Python3_INCLUDE_DIRS} ${Python3_NumPy_INCLUDE_DIRS}
+                   "src/klib" DEPENDS khash.h)
+
+add_custom_command(
+  OUTPUT index.c
+  COMMAND ${Python3_EXECUTABLE} -m cython -3 index.pyx
+  DEPENDS index_class_helper.pxi)
+python3_add_library(index MODULE WITH_SOABI index.c)
+target_include_directories(
+  index PUBLIC ${Python3_INCLUDE_DIRS} ${Python3_NumPy_INCLUDE_DIRS} "src/klib"
+               "./tslibs")
+
+add_custom_command(
+  OUTPUT interval.c
+  COMMAND ${Python3_EXECUTABLE} -m cython -3 interval.pyx
+  DEPENDS intervaltree.pxi)
+python3_add_library(interval MODULE WITH_SOABI interval.c)
+target_include_directories(
+  interval PUBLIC ${Python3_INCLUDE_DIRS} ${Python3_NumPy_INCLUDE_DIRS}
+                  "src/klib" "./tslibs")
+
+add_custom_command(
+  OUTPUT sparse.c
+  COMMAND ${Python3_EXECUTABLE} -m cython -3 sparse.pyx
+  DEPENDS sparse_op_helper.pxi)
+python3_add_library(sparse MODULE WITH_SOABI sparse.c)
+target_include_directories(
+  sparse PUBLIC ${Python3_INCLUDE_DIRS} ${Python3_NumPy_INCLUDE_DIRS}
+                "src/klib")
+
+set(BASIC_LIBRARIES
+    arrays
+    groupby
+    hashing
+    indexing
+    internals
+    reduction
+    ops
+    ops_dispatch
+    properties
+    reshape
+    testing
+    writers)
+foreach(LIB ${BASIC_LIBRARIES})
+  add_custom_command(OUTPUT ${LIB}.c COMMAND ${Python3_EXECUTABLE} -m cython -3
+                                             ${LIB}.pyx)
+  python3_add_library(${LIB} MODULE WITH_SOABI ${LIB}.c)
+  target_include_directories(${LIB} PUBLIC ${Python3_INCLUDE_DIRS}
+                                           ${Python3_NumPy_INCLUDE_DIRS})
+endforeach()
+
+add_subdirectory("tslibs")
+
+add_custom_command(OUTPUT tslib.c COMMAND ${Python3_EXECUTABLE} -m cython -3
+                                          tslib.pyx)
+python3_add_library(tslib ${LIB} MODULE WITH_SOABI tslib.c
+                    tslibs/src/datetime/np_datetime.c)
+target_include_directories(
+  tslib PUBLIC ${Python3_INCLUDE_DIRS} ${Python3_NumPy_INCLUDE_DIRS} "./tslibs")
+
+add_custom_command(OUTPUT missing.c COMMAND ${Python3_EXECUTABLE} -m cython -3
+                                            missing.pyx)
+python3_add_library(missing MODULE WITH_SOABI missing.c)
+target_include_directories(
+  missing PUBLIC ${Python3_INCLUDE_DIRS} ${Python3_NumPy_INCLUDE_DIRS}
+                 "./tslibs")
+
+add_custom_command(OUTPUT lib.c COMMAND ${Python3_EXECUTABLE} -m cython -3
+                                        lib.pyx)
+python3_add_library(lib MODULE WITH_SOABI lib.c src/parser/tokenizer.c)
+target_include_directories(
+  lib PUBLIC ${Python3_INCLUDE_DIRS} ${Python3_NumPy_INCLUDE_DIRS} "src/klib"
+             "./tslibs")
+
+add_custom_command(
+  OUTPUT join.c
+  COMMAND ${Python3_EXECUTABLE} -m cython -3 join.pyx
+  DEPENDS khash_for_primitive_helper.pxi)
+python3_add_library(join MODULE WITH_SOABI join.c)
+target_include_directories(join PUBLIC ${Python3_INCLUDE_DIRS}
+                                       ${Python3_NumPy_INCLUDE_DIRS} "src/klib")
+
+add_custom_command(OUTPUT parsers.c COMMAND ${Python3_EXECUTABLE} -m cython -3
+                                            parsers.pyx)
+python3_add_library(parsers MODULE WITH_SOABI parsers.c src/parser/tokenizer.c
+                    src/parser/io.c)
+target_include_directories(
+  parsers PUBLIC ${Python3_INCLUDE_DIRS} ${Python3_NumPy_INCLUDE_DIRS}
+                 "src/klib" "src")
+
+python3_add_library(
+  ujson
+  MODULE
+  WITH_SOABI
+  src/ujson/python/ujson.c
+  src/ujson/python/objToJSON.c
+  src/ujson/python/date_conversions.c
+  src/ujson/python/JSONtoObj.c
+  src/ujson/lib/ultrajsonenc.c
+  src/ujson/lib/ultrajsondec.c
+  tslibs/src/datetime/np_datetime.c
+  tslibs/src/datetime/np_datetime_strings.c)
+target_include_directories(
+  ujson PUBLIC ${Python3_INCLUDE_DIRS} ${Python3_NumPy_INCLUDE_DIRS}
+               src/ujson/python src/ujson/lib src/datetime)
+
+add_subdirectory("window")
diff --git a/pandas/_libs/generate_templates.py b/pandas/_libs/generate_templates.py
new file mode 100644
index 0000000000000..013568a2812b8
--- /dev/null
+++ b/pandas/_libs/generate_templates.py
@@ -0,0 +1,18 @@
+from __future__ import annotations
+
+from Cython import Tempita
+
+if __name__ == "__main__":
+    for template in (
+        "algos_common_helper.pxi.in",
+        "algos_take_helper.pxi.in",
+        "hashtable_class_helper.pxi.in",
+        "hashtable_func_helper.pxi.in",
+        "index_class_helper.pxi.in",
+        "intervaltree.pxi.in",
+        "khash_for_primitive_helper.pxi.in",
+        "sparse_op_helper.pxi.in",
+    ):
+        pyxcontent = Tempita.sub(open(template).read())
+        with open(template.replace(".in", ""), "w") as outfile:
+            outfile.write(pyxcontent)
diff --git a/pandas/_libs/src/ujson/python/ujson.c b/pandas/_libs/src/ujson/python/ujson.c
index 5d4a5693c0ff6..c9d5a91da2e86 100644
--- a/pandas/_libs/src/ujson/python/ujson.c
+++ b/pandas/_libs/src/ujson/python/ujson.c
@@ -74,7 +74,7 @@ static PyModuleDef moduledef = {
 };
 
 
-PyMODINIT_FUNC PyInit_json(void) {
+PyMODINIT_FUNC PyInit_ujson(void) {
   import_array()
   initObjToJSON();  // TODO(username): clean up, maybe via tp_free?
   return PyModuleDef_Init(&moduledef);
diff --git a/pandas/_libs/tslibs/CMakeLists.txt b/pandas/_libs/tslibs/CMakeLists.txt
new file mode 100644
index 0000000000000..0f8ebdeb8991c
--- /dev/null
+++ b/pandas/_libs/tslibs/CMakeLists.txt
@@ -0,0 +1,43 @@
+set(BASIC_LIBRARIES base ccalendar dtypes nattype strptime timezones)
+foreach(LIB ${BASIC_LIBRARIES})
+  add_custom_command(OUTPUT ${LIB}.c COMMAND ${Python3_EXECUTABLE} -m cython -3
+                                             ${LIB}.pyx)
+  python3_add_library(${LIB} MODULE WITH_SOABI ${LIB}.c)
+  target_include_directories(${LIB} PUBLIC ${Python3_INCLUDE_DIRS}
+                                           ${Python3_NumPy_INCLUDE_DIRS})
+endforeach()
+
+set(NP_DATETIME_REQUIRING
+    conversion
+    fields
+    offsets
+    period
+    timedeltas
+    timestamps
+    tzconversion
+    vectorized)
+foreach(LIB ${NP_DATETIME_REQUIRING})
+  add_custom_command(OUTPUT ${LIB}.c COMMAND ${Python3_EXECUTABLE} -m cython -3
+                                             ${LIB}.pyx)
+  python3_add_library(${LIB} MODULE WITH_SOABI ${LIB}.c
+                      src/datetime/np_datetime.c)
+  target_include_directories(
+    ${LIB} PUBLIC ${Python3_INCLUDE_DIRS} ${Python3_NumPy_INCLUDE_DIRS}
+                  "src/datetime")
+endforeach()
+
+add_custom_command(OUTPUT np_datetime.c COMMAND ${Python3_EXECUTABLE} -m cython
+                                                -3 np_datetime.pyx)
+python3_add_library(
+  np_datetime MODULE WITH_SOABI np_datetime.c src/datetime/np_datetime.c
+  src/datetime/np_datetime_strings.c)
+target_include_directories(np_datetime PUBLIC ${Python3_INCLUDE_DIRS}
+                                              ${Python3_NumPy_INCLUDE_DIRS})
+
+add_custom_command(OUTPUT parsing.c COMMAND ${Python3_EXECUTABLE} -m cython -3
+                                            parsing.pyx)
+python3_add_library(parsing MODULE WITH_SOABI parsing.c
+                    "../src/parser/tokenizer.c")
+target_include_directories(
+  parsing PUBLIC ${Python3_INCLUDE_DIRS} ${Python3_NumPy_INCLUDE_DIRS}
+                 "../src/klib")
diff --git a/pandas/_libs/json.pyi b/pandas/_libs/ujson.pyi
similarity index 100%
rename from pandas/_libs/json.pyi
rename to pandas/_libs/ujson.pyi
diff --git a/pandas/_libs/window/CMakeLists.txt b/pandas/_libs/window/CMakeLists.txt
new file mode 100644
index 0000000000000..862abf42fd89f
--- /dev/null
+++ b/pandas/_libs/window/CMakeLists.txt
@@ -0,0 +1,12 @@
+add_custom_command(OUTPUT indexers.c COMMAND ${Python3_EXECUTABLE} -m cython -3
+                                             indexers.pyx)
+python3_add_library(indexers MODULE WITH_SOABI indexers.c)
+target_include_directories(indexers PUBLIC ${Python3_INCLUDE_DIRS}
+                                           ${Python3_NumPy_INCLUDE_DIRS})
+
+add_custom_command(
+  OUTPUT aggregations.cpp COMMAND ${Python3_EXECUTABLE} -m cython -3 --cplus
+                                  aggregations.pyx)
+python3_add_library(aggregations MODULE WITH_SOABI aggregations.cpp)
+target_include_directories(aggregations PUBLIC ${Python3_INCLUDE_DIRS}
+                                               ${Python3_NumPy_INCLUDE_DIRS})
diff --git a/pandas/io/excel/_odswriter.py b/pandas/io/excel/_odswriter.py
index 185e93591cfe0..694a39ff36d1d 100644
--- a/pandas/io/excel/_odswriter.py
+++ b/pandas/io/excel/_odswriter.py
@@ -10,7 +10,7 @@
     cast,
 )
 
-import pandas._libs.json as json
+import pandas._libs.ujson as json
 from pandas._typing import (
     FilePath,
     StorageOptions,
diff --git a/pandas/io/excel/_xlsxwriter.py b/pandas/io/excel/_xlsxwriter.py
index a3edccd3a5779..4d299c717e23f 100644
--- a/pandas/io/excel/_xlsxwriter.py
+++ b/pandas/io/excel/_xlsxwriter.py
@@ -2,7 +2,7 @@
 
 from typing import Any
 
-import pandas._libs.json as json
+import pandas._libs.ujson as json
 from pandas._typing import (
     FilePath,
     StorageOptions,
diff --git a/pandas/io/excel/_xlwt.py b/pandas/io/excel/_xlwt.py
index 234d9e72de10d..538b5f2a2c5e3 100644
--- a/pandas/io/excel/_xlwt.py
+++ b/pandas/io/excel/_xlwt.py
@@ -7,7 +7,7 @@
     cast,
 )
 
-import pandas._libs.json as json
+import pandas._libs.ujson as json
 from pandas._typing import (
     FilePath,
     StorageOptions,
diff --git a/pandas/io/json/_json.py b/pandas/io/json/_json.py
index 02a0b27f82ef8..6d59ca267af7c 100644
--- a/pandas/io/json/_json.py
+++ b/pandas/io/json/_json.py
@@ -21,8 +21,8 @@
 
 import numpy as np
 
-import pandas._libs.json as json
 from pandas._libs.tslibs import iNaT
+import pandas._libs.ujson as json
 from pandas._typing import (
     CompressionOptions,
     DtypeArg,
diff --git a/pandas/io/json/_table_schema.py b/pandas/io/json/_table_schema.py
index b7a8b5cc82f7a..57a3d5cff3cd7 100644
--- a/pandas/io/json/_table_schema.py
+++ b/pandas/io/json/_table_schema.py
@@ -12,7 +12,7 @@
 )
 import warnings
 
-import pandas._libs.json as json
+import pandas._libs.ujson as json
 from pandas._typing import (
     DtypeObj,
     JSONSerializable,
diff --git a/pandas/io/sas/CMakeLists.txt b/pandas/io/sas/CMakeLists.txt
new file mode 100644
index 0000000000000..a8742edc7a939
--- /dev/null
+++ b/pandas/io/sas/CMakeLists.txt
@@ -0,0 +1,5 @@
+add_custom_command(OUTPUT _sas.c COMMAND ${Python3_EXECUTABLE} -m cython -3
+                                         _sas.pyx)
+python3_add_library(_sas MODULE WITH_SOABI _sas.c)
+target_include_directories(_sas PUBLIC ${Python3_INCLUDE_DIRS}
+                                       ${Python3_NumPy_INCLUDE_DIRS})
diff --git a/pandas/io/sas/sas.pyx b/pandas/io/sas/_sas.pyx
similarity index 100%
rename from pandas/io/sas/sas.pyx
rename to pandas/io/sas/_sas.pyx
diff --git a/pandas/tests/groupby/test_groupby.py b/pandas/tests/groupby/test_groupby.py
index b9f568fc9577b..61b9c1d851c0d 100644
--- a/pandas/tests/groupby/test_groupby.py
+++ b/pandas/tests/groupby/test_groupby.py
@@ -5,7 +5,6 @@
 import pytest
 
 from pandas._libs import lib
-from pandas.compat import IS64
 from pandas.errors import (
     PerformanceWarning,
     SpecificationError,
@@ -2572,7 +2571,6 @@ def test_groupby_series_with_tuple_name():
     tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.xfail(not IS64, reason="GH#38778: fail on 32-bit system")
 @pytest.mark.parametrize(
     "func, values", [("sum", [97.0, 98.0]), ("mean", [24.25, 24.5])]
 )
@@ -2585,7 +2583,6 @@ def test_groupby_numerical_stability_sum_mean(func, values):
     tm.assert_frame_equal(result, expected)
 
 
-@pytest.mark.xfail(not IS64, reason="GH#38778: fail on 32-bit system")
 def test_groupby_numerical_stability_cumsum():
     # GH#38934
     data = [1e16, 1e16, 97, 98, -5e15, -5e15, -5e15, -5e15]
diff --git a/pandas/tests/io/json/test_ujson.py b/pandas/tests/io/json/test_ujson.py
index ae13d8d5fb180..ff43933be1232 100644
--- a/pandas/tests/io/json/test_ujson.py
+++ b/pandas/tests/io/json/test_ujson.py
@@ -12,7 +12,7 @@
 import pytest
 import pytz
 
-import pandas._libs.json as ujson
+import pandas._libs.ujson as ujson
 from pandas.compat import (
     IS64,
     is_platform_windows,
diff --git a/pandas/tests/io/parser/common/test_float.py b/pandas/tests/io/parser/common/test_float.py
index 2ca98de914f9e..e245b2ca019ee 100644
--- a/pandas/tests/io/parser/common/test_float.py
+++ b/pandas/tests/io/parser/common/test_float.py
@@ -7,7 +7,10 @@
 import numpy as np
 import pytest
 
-from pandas.compat import is_platform_linux
+from pandas.compat import (
+    is_platform_linux,
+    is_platform_mac,
+)
 
 from pandas import DataFrame
 import pandas._testing as tm
@@ -53,8 +56,8 @@ def test_too_many_exponent_digits(all_parsers_all_precisions, exp, request):
     data = f"data\n10E{exp}"
     result = parser.read_csv(StringIO(data), float_precision=precision)
     if precision == "round_trip":
-        if exp == 999999999999999999 and is_platform_linux():
-            mark = pytest.mark.xfail(reason="GH38794, on Linux gives object result")
+        if exp == 999999999999999999 and (is_platform_linux() or is_platform_mac()):
+            mark = pytest.mark.xfail(reason="GH38794, on Unix gives object result")
             request.node.add_marker(mark)
 
         value = np.inf if exp > 0 else 0.0
diff --git a/pandas/tests/io/parser/test_c_parser_only.py b/pandas/tests/io/parser/test_c_parser_only.py
index 9a81790ca3bb0..6d92225f9458d 100644
--- a/pandas/tests/io/parser/test_c_parser_only.py
+++ b/pandas/tests/io/parser/test_c_parser_only.py
@@ -17,10 +17,7 @@
 import numpy as np
 import pytest
 
-from pandas.compat import (
-    IS64,
-    is_ci_environment,
-)
+from pandas.compat import is_ci_environment
 from pandas.errors import ParserError
 import pandas.util._test_decorators as td
 
@@ -678,10 +675,7 @@ def test_float_precision_options(c_parser_only):
 
     df3 = parser.read_csv(StringIO(s), float_precision="legacy")
 
-    if IS64:
-        assert not df.iloc[0, 0] == df3.iloc[0, 0]
-    else:
-        assert df.iloc[0, 0] == df3.iloc[0, 0]
+    assert not df.iloc[0, 0] == df3.iloc[0, 0]
 
     msg = "Unrecognized float_precision option: junk"
 
diff --git a/pandas/tests/window/test_rolling.py b/pandas/tests/window/test_rolling.py
index c9ec2985488be..b229d1b8db51e 100644
--- a/pandas/tests/window/test_rolling.py
+++ b/pandas/tests/window/test_rolling.py
@@ -7,6 +7,7 @@
 import pytest
 
 from pandas.compat import (
+    IS64,
     is_platform_arm,
     is_platform_mac,
 )
@@ -1191,7 +1192,9 @@ def test_rolling_sem(frame_or_series):
     tm.assert_series_equal(result, expected)
 
 
-@pytest.mark.xfail(is_platform_arm() and not is_platform_mac(), reason="GH 38921")
+@pytest.mark.xfail(
+    (is_platform_arm() and not is_platform_mac()) or not IS64, reason="GH 38921"
+)
 @pytest.mark.parametrize(
     ("func", "third_value", "values"),
     [
diff --git a/pyproject.toml b/pyproject.toml
index 67c56123a847c..81aa906bdd2bd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -2,14 +2,15 @@
 # Minimum requirements for the build system to execute.
 # See https://github.com/scipy/scipy/pull/12940 for the AIX issue.
 requires = [
+    "cmake>=3.18.0",
     "setuptools>=51.0.0",
     "wheel",
     "Cython>=0.29.32,<3",  # Note: sync with setup.py, environment.yml and asv.conf.json
     "oldest-supported-numpy>=0.10"
 ]
-# uncomment to enable pep517 after versioneer problem is fixed.
-# https://github.com/python-versioneer/python-versioneer/issues/193
-# build-backend = "setuptools.build_meta"
+
+build-backend = "build_backend"
+backend-path = ["build_support"]
 
 [tool.black]
 target-version = ['py38', 'py39']
diff --git a/requirements-dev.txt b/requirements-dev.txt
index 60dd738e43ba3..3a59ebc79e315 100644
--- a/requirements-dev.txt
+++ b/requirements-dev.txt
@@ -62,6 +62,7 @@ torch
 moto
 flask
 asv
+cmake>=3.18.0
 black==22.3.0
 cpplint
 flake8==5.0.4
diff --git a/setup.py b/setup.py
old mode 100755
new mode 100644
index 12e8aa36c3794..79e4fea9fdf36
--- a/setup.py
+++ b/setup.py
@@ -5,662 +5,21 @@
 (https://github.com/zeromq/pyzmq) which have been permitted for use under the
 BSD license. Parts are from lxml (https://github.com/lxml/lxml)
 """
-
-import argparse
-import multiprocessing
 import os
-from os.path import join as pjoin
-import platform
-import shutil
 import sys
-from sysconfig import get_config_vars
 
-import numpy
-from pkg_resources import parse_version
-from setuptools import (
-    Command,
-    Extension,
-    setup,
-)
-from setuptools.command.build_ext import build_ext as _build_ext
+from setuptools import setup
 
+# uncomment to enable pep517 after versioneer problem is fixed.
+# https://github.com/python-versioneer/python-versioneer/issues/193
+sys.path.insert(0, os.path.dirname(__file__))
 import versioneer
 
 cmdclass = versioneer.get_cmdclass()
 
 
-def is_platform_windows():
-    return sys.platform == "win32" or sys.platform == "cygwin"
-
-
-def is_platform_mac():
-    return sys.platform == "darwin"
-
-
-# note: sync with pyproject.toml, environment.yml and asv.conf.json
-min_cython_ver = "0.29.32"
-
-try:
-    from Cython import (
-        Tempita,
-        __version__ as _CYTHON_VERSION,
-    )
-    from Cython.Build import cythonize
-
-    _CYTHON_INSTALLED = parse_version(_CYTHON_VERSION) >= parse_version(min_cython_ver)
-except ImportError:
-    _CYTHON_VERSION = None
-    _CYTHON_INSTALLED = False
-    cythonize = lambda x, *args, **kwargs: x  # dummy func
-
-
-_pxi_dep_template = {
-    "algos": ["_libs/algos_common_helper.pxi.in", "_libs/algos_take_helper.pxi.in"],
-    "hashtable": [
-        "_libs/hashtable_class_helper.pxi.in",
-        "_libs/hashtable_func_helper.pxi.in",
-        "_libs/khash_for_primitive_helper.pxi.in",
-    ],
-    "index": ["_libs/index_class_helper.pxi.in"],
-    "sparse": ["_libs/sparse_op_helper.pxi.in"],
-    "interval": ["_libs/intervaltree.pxi.in"],
-}
-
-_pxifiles = []
-_pxi_dep = {}
-for module, files in _pxi_dep_template.items():
-    pxi_files = [pjoin("pandas", x) for x in files]
-    _pxifiles.extend(pxi_files)
-    _pxi_dep[module] = pxi_files
-
-
-class build_ext(_build_ext):
-    @classmethod
-    def render_templates(cls, pxifiles):
-        for pxifile in pxifiles:
-            # build pxifiles first, template extension must be .pxi.in
-            assert pxifile.endswith(".pxi.in")
-            outfile = pxifile[:-3]
-
-            if (
-                os.path.exists(outfile)
-                and os.stat(pxifile).st_mtime < os.stat(outfile).st_mtime
-            ):
-                # if .pxi.in is not updated, no need to output .pxi
-                continue
-
-            with open(pxifile) as f:
-                tmpl = f.read()
-            pyxcontent = Tempita.sub(tmpl)
-
-            with open(outfile, "w") as f:
-                f.write(pyxcontent)
-
-    def build_extensions(self):
-        # if building from c files, don't need to
-        # generate template output
-        if _CYTHON_INSTALLED:
-            self.render_templates(_pxifiles)
-
-        super().build_extensions()
-
-
-class CleanCommand(Command):
-    """Custom command to clean the .so and .pyc files."""
-
-    user_options = [("all", "a", "")]
-
-    def initialize_options(self):
-        self.all = True
-        self._clean_me = []
-        self._clean_trees = []
-
-        base = pjoin("pandas", "_libs", "src")
-        tsbase = pjoin("pandas", "_libs", "tslibs", "src")
-        dt = pjoin(tsbase, "datetime")
-        util = pjoin("pandas", "util")
-        parser = pjoin(base, "parser")
-        ujson_python = pjoin(base, "ujson", "python")
-        ujson_lib = pjoin(base, "ujson", "lib")
-        self._clean_exclude = [
-            pjoin(dt, "np_datetime.c"),
-            pjoin(dt, "np_datetime_strings.c"),
-            pjoin(parser, "tokenizer.c"),
-            pjoin(parser, "io.c"),
-            pjoin(ujson_python, "ujson.c"),
-            pjoin(ujson_python, "objToJSON.c"),
-            pjoin(ujson_python, "JSONtoObj.c"),
-            pjoin(ujson_python, "date_conversions.c"),
-            pjoin(ujson_lib, "ultrajsonenc.c"),
-            pjoin(ujson_lib, "ultrajsondec.c"),
-            pjoin(util, "move.c"),
-        ]
-
-        for root, dirs, files in os.walk("pandas"):
-            for f in files:
-                filepath = pjoin(root, f)
-                if filepath in self._clean_exclude:
-                    continue
-
-                if os.path.splitext(f)[-1] in (
-                    ".pyc",
-                    ".so",
-                    ".o",
-                    ".pyo",
-                    ".pyd",
-                    ".c",
-                    ".cpp",
-                    ".orig",
-                ):
-                    self._clean_me.append(filepath)
-            for d in dirs:
-                if d == "__pycache__":
-                    self._clean_trees.append(pjoin(root, d))
-
-        # clean the generated pxi files
-        for pxifile in _pxifiles:
-            pxifile = pxifile.replace(".pxi.in", ".pxi")
-            self._clean_me.append(pxifile)
-
-        for d in ("build", "dist"):
-            if os.path.exists(d):
-                self._clean_trees.append(d)
-
-    def finalize_options(self):
-        pass
-
-    def run(self):
-        for clean_me in self._clean_me:
-            try:
-                os.unlink(clean_me)
-            except OSError:
-                pass
-        for clean_tree in self._clean_trees:
-            try:
-                shutil.rmtree(clean_tree)
-            except OSError:
-                pass
-
-
-# we need to inherit from the versioneer
-# class as it encodes the version info
-sdist_class = cmdclass["sdist"]
-
-
-class CheckSDist(sdist_class):
-    """Custom sdist that ensures Cython has compiled all pyx files to c."""
-
-    _pyxfiles = [
-        "pandas/_libs/arrays.pyx",
-        "pandas/_libs/lib.pyx",
-        "pandas/_libs/hashtable.pyx",
-        "pandas/_libs/tslib.pyx",
-        "pandas/_libs/index.pyx",
-        "pandas/_libs/internals.pyx",
-        "pandas/_libs/algos.pyx",
-        "pandas/_libs/join.pyx",
-        "pandas/_libs/indexing.pyx",
-        "pandas/_libs/interval.pyx",
-        "pandas/_libs/hashing.pyx",
-        "pandas/_libs/missing.pyx",
-        "pandas/_libs/reduction.pyx",
-        "pandas/_libs/testing.pyx",
-        "pandas/_libs/sparse.pyx",
-        "pandas/_libs/ops.pyx",
-        "pandas/_libs/parsers.pyx",
-        "pandas/_libs/tslibs/base.pyx",
-        "pandas/_libs/tslibs/ccalendar.pyx",
-        "pandas/_libs/tslibs/dtypes.pyx",
-        "pandas/_libs/tslibs/period.pyx",
-        "pandas/_libs/tslibs/strptime.pyx",
-        "pandas/_libs/tslibs/np_datetime.pyx",
-        "pandas/_libs/tslibs/timedeltas.pyx",
-        "pandas/_libs/tslibs/timestamps.pyx",
-        "pandas/_libs/tslibs/timezones.pyx",
-        "pandas/_libs/tslibs/conversion.pyx",
-        "pandas/_libs/tslibs/fields.pyx",
-        "pandas/_libs/tslibs/offsets.pyx",
-        "pandas/_libs/tslibs/parsing.pyx",
-        "pandas/_libs/tslibs/tzconversion.pyx",
-        "pandas/_libs/tslibs/vectorized.pyx",
-        "pandas/_libs/window/indexers.pyx",
-        "pandas/_libs/writers.pyx",
-        "pandas/io/sas/sas.pyx",
-    ]
-
-    _cpp_pyxfiles = [
-        "pandas/_libs/window/aggregations.pyx",
-    ]
-
-    def initialize_options(self):
-        sdist_class.initialize_options(self)
-
-    def run(self):
-        if "cython" in cmdclass:
-            self.run_command("cython")
-        else:
-            # If we are not running cython then
-            # compile the extensions correctly
-            pyx_files = [(self._pyxfiles, "c"), (self._cpp_pyxfiles, "cpp")]
-
-            for pyxfiles, extension in pyx_files:
-                for pyxfile in pyxfiles:
-                    sourcefile = pyxfile[:-3] + extension
-                    msg = (
-                        f"{extension}-source file '{sourcefile}' not found.\n"
-                        "Run 'setup.py cython' before sdist."
-                    )
-                    assert os.path.isfile(sourcefile), msg
-        sdist_class.run(self)
-
-
-class CheckingBuildExt(build_ext):
-    """
-    Subclass build_ext to get clearer report if Cython is necessary.
-    """
-
-    def check_cython_extensions(self, extensions):
-        for ext in extensions:
-            for src in ext.sources:
-                if not os.path.exists(src):
-                    print(f"{ext.name}: -> [{ext.sources}]")
-                    raise Exception(
-                        f"""Cython-generated file '{src}' not found.
-                Cython is required to compile pandas from a development branch.
-                Please install Cython or download a release package of pandas.
-                """
-                    )
-
-    def build_extensions(self):
-        self.check_cython_extensions(self.extensions)
-        build_ext.build_extensions(self)
-
-
-class CythonCommand(build_ext):
-    """
-    Custom command subclassed from Cython.Distutils.build_ext
-    to compile pyx->c, and stop there. All this does is override the
-    C-compile method build_extension() with a no-op.
-    """
-
-    def build_extension(self, ext):
-        pass
-
-
-class DummyBuildSrc(Command):
-    """numpy's build_src command interferes with Cython's build_ext."""
-
-    user_options = []
-
-    def initialize_options(self):
-        self.py_modules_dict = {}
-
-    def finalize_options(self):
-        pass
-
-    def run(self):
-        pass
-
-
-cmdclass["clean"] = CleanCommand
-cmdclass["build_ext"] = CheckingBuildExt
-
-if _CYTHON_INSTALLED:
-    suffix = ".pyx"
-    cmdclass["cython"] = CythonCommand
-else:
-    suffix = ".c"
-    cmdclass["build_src"] = DummyBuildSrc
-
-# ----------------------------------------------------------------------
-# Preparation of compiler arguments
-
-debugging_symbols_requested = "--with-debugging-symbols" in sys.argv
-if debugging_symbols_requested:
-    sys.argv.remove("--with-debugging-symbols")
-
-
-if sys.byteorder == "big":
-    endian_macro = [("__BIG_ENDIAN__", "1")]
-else:
-    endian_macro = [("__LITTLE_ENDIAN__", "1")]
-
-
-extra_compile_args = []
-extra_link_args = []
-if is_platform_windows():
-    if debugging_symbols_requested:
-        extra_compile_args.append("/Z7")
-        extra_link_args.append("/DEBUG")
-else:
-    # PANDAS_CI=1 is set in CI
-    if os.environ.get("PANDAS_CI", "0") == "1":
-        extra_compile_args.append("-Werror")
-    if debugging_symbols_requested:
-        extra_compile_args.append("-g")
-        extra_compile_args.append("-UNDEBUG")
-        extra_compile_args.append("-O0")
-
-# Build for at least macOS 10.9 when compiling on a 10.9 system or above,
-# overriding CPython distuitls behaviour which is to target the version that
-# python was built for. This may be overridden by setting
-# MACOSX_DEPLOYMENT_TARGET before calling setup.py
-if is_platform_mac():
-    if "MACOSX_DEPLOYMENT_TARGET" not in os.environ:
-        current_system = platform.mac_ver()[0]
-        python_target = get_config_vars().get(
-            "MACOSX_DEPLOYMENT_TARGET", current_system
-        )
-        target_macos_version = "10.9"
-        parsed_macos_version = parse_version(target_macos_version)
-        if (
-            parse_version(str(python_target)) < parsed_macos_version
-            and parse_version(current_system) >= parsed_macos_version
-        ):
-            os.environ["MACOSX_DEPLOYMENT_TARGET"] = target_macos_version
-
-    if sys.version_info[:2] == (3, 8):  # GH 33239
-        extra_compile_args.append("-Wno-error=deprecated-declarations")
-
-    # https://github.com/pandas-dev/pandas/issues/35559
-    extra_compile_args.append("-Wno-error=unreachable-code")
-
-# enable coverage by building cython files by setting the environment variable
-# "PANDAS_CYTHON_COVERAGE" (with a Truthy value) or by running build_ext
-# with `--with-cython-coverage`enabled
-linetrace = os.environ.get("PANDAS_CYTHON_COVERAGE", False)
-if "--with-cython-coverage" in sys.argv:
-    linetrace = True
-    sys.argv.remove("--with-cython-coverage")
-
-# Note: if not using `cythonize`, coverage can be enabled by
-# pinning `ext.cython_directives = directives` to each ext in extensions.
-# github.com/cython/cython/wiki/enhancements-compilerdirectives#in-setuppy
-directives = {"linetrace": False, "language_level": 3}
-macros = []
-if linetrace:
-    # https://pypkg.com/pypi/pytest-cython/f/tests/example-project/setup.py
-    directives["linetrace"] = True
-    macros = [("CYTHON_TRACE", "1"), ("CYTHON_TRACE_NOGIL", "1")]
-
-# silence build warnings about deprecated API usage
-# we can't do anything about these warnings because they stem from
-# cython+numpy version mismatches.
-macros.append(("NPY_NO_DEPRECATED_API", "0"))
-
-
-# ----------------------------------------------------------------------
-# Specification of Dependencies
-
-# TODO(cython#4518): Need to check to see if e.g. `linetrace` has changed and
-#  possibly re-compile.
-def maybe_cythonize(extensions, *args, **kwargs):
-    """
-    Render tempita templates before calling cythonize. This is skipped for
-
-    * clean
-    * sdist
-    """
-    if "clean" in sys.argv or "sdist" in sys.argv:
-        # See https://github.com/cython/cython/issues/1495
-        return extensions
-
-    elif not _CYTHON_INSTALLED:
-        # GH#28836 raise a helfpul error message
-        if _CYTHON_VERSION:
-            raise RuntimeError(
-                f"Cannot cythonize with old Cython version ({_CYTHON_VERSION} "
-                f"installed, needs {min_cython_ver})"
-            )
-        raise RuntimeError("Cannot cythonize without Cython installed.")
-
-    # reuse any parallel arguments provided for compilation to cythonize
-    parser = argparse.ArgumentParser()
-    parser.add_argument("--parallel", "-j", type=int, default=1)
-    parsed, _ = parser.parse_known_args()
-
-    kwargs["nthreads"] = parsed.parallel
-    build_ext.render_templates(_pxifiles)
-    return cythonize(extensions, *args, **kwargs)
-
-
-def srcpath(name=None, suffix=".pyx", subdir="src"):
-    return pjoin("pandas", subdir, name + suffix)
-
-
-lib_depends = ["pandas/_libs/src/parse_helper.h"]
-
-klib_include = ["pandas/_libs/src/klib"]
-
-tseries_depends = [
-    "pandas/_libs/tslibs/src/datetime/np_datetime.h",
-    "pandas/_libs/tslibs/src/datetime/np_datetime_strings.h",
-]
-
-ext_data = {
-    "_libs.algos": {
-        "pyxfile": "_libs/algos",
-        "include": klib_include,
-        "depends": _pxi_dep["algos"],
-    },
-    "_libs.arrays": {"pyxfile": "_libs/arrays"},
-    "_libs.groupby": {"pyxfile": "_libs/groupby"},
-    "_libs.hashing": {"pyxfile": "_libs/hashing", "depends": []},
-    "_libs.hashtable": {
-        "pyxfile": "_libs/hashtable",
-        "include": klib_include,
-        "depends": (
-            ["pandas/_libs/src/klib/khash_python.h", "pandas/_libs/src/klib/khash.h"]
-            + _pxi_dep["hashtable"]
-        ),
-    },
-    "_libs.index": {
-        "pyxfile": "_libs/index",
-        "include": klib_include,
-        "depends": _pxi_dep["index"],
-    },
-    "_libs.indexing": {"pyxfile": "_libs/indexing"},
-    "_libs.internals": {"pyxfile": "_libs/internals"},
-    "_libs.interval": {
-        "pyxfile": "_libs/interval",
-        "include": klib_include,
-        "depends": _pxi_dep["interval"],
-    },
-    "_libs.join": {"pyxfile": "_libs/join", "include": klib_include},
-    "_libs.lib": {
-        "pyxfile": "_libs/lib",
-        "depends": lib_depends + tseries_depends,
-        "include": klib_include,  # due to tokenizer import
-        "sources": ["pandas/_libs/src/parser/tokenizer.c"],
-    },
-    "_libs.missing": {"pyxfile": "_libs/missing", "depends": tseries_depends},
-    "_libs.parsers": {
-        "pyxfile": "_libs/parsers",
-        "include": klib_include + ["pandas/_libs/src"],
-        "depends": [
-            "pandas/_libs/src/parser/tokenizer.h",
-            "pandas/_libs/src/parser/io.h",
-        ],
-        "sources": [
-            "pandas/_libs/src/parser/tokenizer.c",
-            "pandas/_libs/src/parser/io.c",
-        ],
-    },
-    "_libs.reduction": {"pyxfile": "_libs/reduction"},
-    "_libs.ops": {"pyxfile": "_libs/ops"},
-    "_libs.ops_dispatch": {"pyxfile": "_libs/ops_dispatch"},
-    "_libs.properties": {"pyxfile": "_libs/properties"},
-    "_libs.reshape": {"pyxfile": "_libs/reshape", "depends": []},
-    "_libs.sparse": {"pyxfile": "_libs/sparse", "depends": _pxi_dep["sparse"]},
-    "_libs.tslib": {
-        "pyxfile": "_libs/tslib",
-        "depends": tseries_depends,
-        "sources": ["pandas/_libs/tslibs/src/datetime/np_datetime.c"],
-    },
-    "_libs.tslibs.base": {"pyxfile": "_libs/tslibs/base"},
-    "_libs.tslibs.ccalendar": {"pyxfile": "_libs/tslibs/ccalendar"},
-    "_libs.tslibs.dtypes": {"pyxfile": "_libs/tslibs/dtypes"},
-    "_libs.tslibs.conversion": {
-        "pyxfile": "_libs/tslibs/conversion",
-        "depends": tseries_depends,
-        "sources": ["pandas/_libs/tslibs/src/datetime/np_datetime.c"],
-    },
-    "_libs.tslibs.fields": {
-        "pyxfile": "_libs/tslibs/fields",
-        "depends": tseries_depends,
-        "sources": ["pandas/_libs/tslibs/src/datetime/np_datetime.c"],
-    },
-    "_libs.tslibs.nattype": {"pyxfile": "_libs/tslibs/nattype"},
-    "_libs.tslibs.np_datetime": {
-        "pyxfile": "_libs/tslibs/np_datetime",
-        "depends": tseries_depends,
-        "sources": [
-            "pandas/_libs/tslibs/src/datetime/np_datetime.c",
-            "pandas/_libs/tslibs/src/datetime/np_datetime_strings.c",
-        ],
-    },
-    "_libs.tslibs.offsets": {
-        "pyxfile": "_libs/tslibs/offsets",
-        "depends": tseries_depends,
-        "sources": ["pandas/_libs/tslibs/src/datetime/np_datetime.c"],
-    },
-    "_libs.tslibs.parsing": {
-        "pyxfile": "_libs/tslibs/parsing",
-        "include": klib_include,
-        "depends": ["pandas/_libs/src/parser/tokenizer.h"],
-        "sources": ["pandas/_libs/src/parser/tokenizer.c"],
-    },
-    "_libs.tslibs.period": {
-        "pyxfile": "_libs/tslibs/period",
-        "depends": tseries_depends,
-        "sources": ["pandas/_libs/tslibs/src/datetime/np_datetime.c"],
-    },
-    "_libs.tslibs.strptime": {
-        "pyxfile": "_libs/tslibs/strptime",
-        "depends": tseries_depends,
-    },
-    "_libs.tslibs.timedeltas": {
-        "pyxfile": "_libs/tslibs/timedeltas",
-        "depends": tseries_depends,
-        "sources": ["pandas/_libs/tslibs/src/datetime/np_datetime.c"],
-    },
-    "_libs.tslibs.timestamps": {
-        "pyxfile": "_libs/tslibs/timestamps",
-        "depends": tseries_depends,
-        "sources": ["pandas/_libs/tslibs/src/datetime/np_datetime.c"],
-    },
-    "_libs.tslibs.timezones": {"pyxfile": "_libs/tslibs/timezones"},
-    "_libs.tslibs.tzconversion": {
-        "pyxfile": "_libs/tslibs/tzconversion",
-        "depends": tseries_depends,
-        "sources": ["pandas/_libs/tslibs/src/datetime/np_datetime.c"],
-    },
-    "_libs.tslibs.vectorized": {
-        "pyxfile": "_libs/tslibs/vectorized",
-        "depends": tseries_depends,
-        "sources": ["pandas/_libs/tslibs/src/datetime/np_datetime.c"],
-    },
-    "_libs.testing": {"pyxfile": "_libs/testing"},
-    "_libs.window.aggregations": {
-        "pyxfile": "_libs/window/aggregations",
-        "language": "c++",
-        "suffix": ".cpp",
-        "depends": ["pandas/_libs/src/skiplist.h"],
-    },
-    "_libs.window.indexers": {"pyxfile": "_libs/window/indexers"},
-    "_libs.writers": {"pyxfile": "_libs/writers"},
-    "io.sas._sas": {"pyxfile": "io/sas/sas"},
-}
-
-extensions = []
-
-for name, data in ext_data.items():
-    source_suffix = suffix if suffix == ".pyx" else data.get("suffix", ".c")
-
-    sources = [srcpath(data["pyxfile"], suffix=source_suffix, subdir="")]
-
-    sources.extend(data.get("sources", []))
-
-    include = data.get("include", [])
-    include.append(numpy.get_include())
-
-    undef_macros = []
-
-    if (
-        sys.platform == "zos"
-        and data.get("language") == "c++"
-        and os.path.basename(os.environ.get("CXX", "/bin/xlc++")) in ("xlc", "xlc++")
-    ):
-        data.get("macros", macros).append(("__s390__", "1"))
-        extra_compile_args.append("-qlanglvl=extended0x:nolibext")
-        undef_macros.append("_POSIX_THREADS")
-
-    obj = Extension(
-        f"pandas.{name}",
-        sources=sources,
-        depends=data.get("depends", []),
-        include_dirs=include,
-        language=data.get("language", "c"),
-        define_macros=data.get("macros", macros),
-        extra_compile_args=extra_compile_args,
-        extra_link_args=extra_link_args,
-        undef_macros=undef_macros,
-    )
-
-    extensions.append(obj)
-
-# ----------------------------------------------------------------------
-# ujson
-
-if suffix == ".pyx":
-    # undo dumb setuptools bug clobbering .pyx sources back to .c
-    for ext in extensions:
-        if ext.sources[0].endswith((".c", ".cpp")):
-            root, _ = os.path.splitext(ext.sources[0])
-            ext.sources[0] = root + suffix
-
-ujson_ext = Extension(
-    "pandas._libs.json",
-    depends=[
-        "pandas/_libs/src/ujson/lib/ultrajson.h",
-        "pandas/_libs/src/ujson/python/date_conversions.h",
-    ],
-    sources=(
-        [
-            "pandas/_libs/src/ujson/python/ujson.c",
-            "pandas/_libs/src/ujson/python/objToJSON.c",
-            "pandas/_libs/src/ujson/python/date_conversions.c",
-            "pandas/_libs/src/ujson/python/JSONtoObj.c",
-            "pandas/_libs/src/ujson/lib/ultrajsonenc.c",
-            "pandas/_libs/src/ujson/lib/ultrajsondec.c",
-        ]
-        + [
-            "pandas/_libs/tslibs/src/datetime/np_datetime.c",
-            "pandas/_libs/tslibs/src/datetime/np_datetime_strings.c",
-        ]
-    ),
-    include_dirs=[
-        "pandas/_libs/src/ujson/python",
-        "pandas/_libs/src/ujson/lib",
-        "pandas/_libs/src/datetime",
-        numpy.get_include(),
-    ],
-    extra_compile_args=(["-D_GNU_SOURCE"] + extra_compile_args),
-    extra_link_args=extra_link_args,
-    define_macros=macros,
-)
-
-
-extensions.append(ujson_ext)
-
-# ----------------------------------------------------------------------
-
-
 if __name__ == "__main__":
-    # Freeze to support parallel compilation when using spawn instead of fork
-    multiprocessing.freeze_support()
     setup(
         version=versioneer.get_version(),
-        ext_modules=maybe_cythonize(extensions, compiler_directives=directives),
         cmdclass=cmdclass,
     )