diff --git a/conda_smithy/configure_feedstock.py b/conda_smithy/configure_feedstock.py
index a50fd6395..52b5cb59f 100644
--- a/conda_smithy/configure_feedstock.py
+++ b/conda_smithy/configure_feedstock.py
@@ -2039,9 +2039,12 @@ def _azure_specific_setup(jinja_env, forge_config, forge_dir, platform):
             }
         )
         # fmt: off
-        if "docker_image" in data["config"] and platform == "linux":
-            config_rendered["DOCKER_IMAGE"] = data["config"]["docker_image"][-1]
-        if platform == "osx":
+        if platform == "linux":
+            if docker_image := data.get("config", {}).get("docker_image"):
+                config_rendered["DOCKER_IMAGE"] = docker_image[-1]
+        elif platform == "win":
+            config_rendered["build_platform"] = data["build_platform"]
+        elif platform == "osx":
             if data["build_platform"] == "osx-64":
                 config_rendered["VMIMAGE"] = "macOS-15"
             elif data["build_platform"] == "osx-arm64":
diff --git a/conda_smithy/templates/azure-pipelines-win.yml.tmpl b/conda_smithy/templates/azure-pipelines-win.yml.tmpl
index 397ab1835..0e2b8c02b 100644
--- a/conda_smithy/templates/azure-pipelines-win.yml.tmpl
+++ b/conda_smithy/templates/azure-pipelines-win.yml.tmpl
@@ -90,6 +90,7 @@ jobs:
 {%- endif %}
         UPLOAD_PACKAGES: $(UPLOAD_PACKAGES)
         UPLOAD_TEMP: $(UPLOAD_TEMP)
+        build_platform: $(build_platform)
         flow_run_id: azure_$(Build.BuildNumber).$(System.JobAttempt)
         remote_url: $(Build.Repository.Uri)
         sha: $(Build.SourceVersion)
diff --git a/conda_smithy/templates/build_steps.sh.tmpl b/conda_smithy/templates/build_steps.sh.tmpl
index cec63de6f..fd918de16 100644
--- a/conda_smithy/templates/build_steps.sh.tmpl
+++ b/conda_smithy/templates/build_steps.sh.tmpl
@@ -134,7 +134,7 @@ if [[ "${BUILD_WITH_CONDA_DEBUG:-0}" == 1 ]]; then
     #   - --clobber-file vs. none
     #   - none vs. --target-platform
     {%- if conda_build_tool.startswith("conda-build") %}
-    conda debug \
+    CONDA_SUBDIR="${BUILD_PLATFORM}" conda debug \
         "${RECIPE_ROOT}" \
         -m "${CI_SUPPORT}/${CONFIG}.yaml" \
         ${EXTRA_CB_OPTIONS:-} \
@@ -150,6 +150,7 @@ if [[ "${BUILD_WITH_CONDA_DEBUG:-0}" == 1 ]]; then
         -m "${CI_SUPPORT}/${CONFIG}.yaml" \
         ${EXTRA_CB_OPTIONS:-} \
         ${BUILD_OUTPUT_ID:+--output-name "${BUILD_OUTPUT_ID}"} \
+        --build-platform "${BUILD_PLATFORM}" \
         --target-platform "${HOST_PLATFORM}"
 
     rattler-build debug shell
@@ -165,7 +166,7 @@ else
     #   - none vs. --target-platform
     #   - --extra-meta a=b c=d vs. --extra-meta a=b --extra-meta c=d
     {%- if conda_build_tool != "rattler-build" %}
-    {{ BUILD_CMD }} \
+    CONDA_SUBDIR="${BUILD_PLATFORM}" {{ BUILD_CMD }} \
         "${RECIPE_ROOT}" \
         -m "${CI_SUPPORT}/${CONFIG}.yaml" \
         ${EXTRA_CB_OPTIONS:-} \
@@ -179,6 +180,7 @@ else
         --recipe "${RECIPE_ROOT}" \
         -m "${CI_SUPPORT}/${CONFIG}.yaml" \
         ${EXTRA_CB_OPTIONS:-} \
+        --build-platform "${BUILD_PLATFORM}" \
         --target-platform "${HOST_PLATFORM}" \
         --extra-meta flow_run_id="${flow_run_id:-}" \
         --extra-meta remote_url="${remote_url:-}" \
diff --git a/conda_smithy/templates/github-actions.yml.tmpl b/conda_smithy/templates/github-actions.yml.tmpl
index 1ab534786..cd3152662 100644
--- a/conda_smithy/templates/github-actions.yml.tmpl
+++ b/conda_smithy/templates/github-actions.yml.tmpl
@@ -61,6 +61,9 @@ jobs:
         {%- endif %}
             STORE_BUILD_ARTIFACTS: {{ data.store_build_artifacts is true }}
             UPLOAD_PACKAGES: {{ data.upload }}
+        {%- if data.build_platform.startswith("win") %}
+            build_platform: {{ data.build_platform }}
+        {%- endif %}
             build_workspace_dir: {{ data.build_workspace_dir }}
             docker_run_args: {{ data.docker_run_args }}
             free_disk_space: {{ data.free_disk_space }}
@@ -231,6 +234,8 @@ jobs:
         set "sha=%GITHUB_SHA%"
         call ".scripts\run_win_build.bat"
       env:
+        {#- BUILD_PLATFORM needed to distinguish emulated/native builds #}
+        BUILD_PLATFORM: {% raw %}${{ matrix.build_platform }}{% endraw %}
         CI: github_actions
         CONDA_BLD_PATH: {% raw %}${{ matrix.build_workspace_dir }}{% endraw %}
         CONFIG: {% raw %}${{ matrix.CONFIG }}{% endraw %}
diff --git a/conda_smithy/templates/run_osx_build.sh.tmpl b/conda_smithy/templates/run_osx_build.sh.tmpl
index 7ac3e0402..0a6166ab5 100644
--- a/conda_smithy/templates/run_osx_build.sh.tmpl
+++ b/conda_smithy/templates/run_osx_build.sh.tmpl
@@ -165,7 +165,7 @@ if [[ "${BUILD_WITH_CONDA_DEBUG:-0}" == 1 ]]; then
     if [[ "x${BUILD_OUTPUT_ID:-}" != "x" ]]; then
         EXTRA_CB_OPTIONS="${EXTRA_CB_OPTIONS:-} --output-id ${BUILD_OUTPUT_ID}"
     fi
-    conda debug ./{{ recipe_dir }} -m ./.ci_support/${CONFIG}.yaml \
+    CONDA_SUBDIR="${BUILD_PLATFORM}" conda debug ./{{ recipe_dir }} -m ./.ci_support/${CONFIG}.yaml \
         ${EXTRA_CB_OPTIONS:-} \
         --clobber-file ./.ci_support/clobber_${CONFIG}.yaml
 
@@ -176,6 +176,7 @@ if [[ "${BUILD_WITH_CONDA_DEBUG:-0}" == 1 ]]; then
     rattler-build debug setup \
         --recipe ./{{ recipe_dir }} \
         -m ./.ci_support/${CONFIG}.yaml \
+        --build-platform "${BUILD_PLATFORM}" \
         --target-platform "${HOST_PLATFORM}" \
         ${BUILD_OUTPUT_ID:+--output-name "${BUILD_OUTPUT_ID}"} \
         ${EXTRA_CB_OPTIONS:-}
@@ -189,7 +190,7 @@ else
     fi
 {% endif %}
     {%- if conda_build_tool != "rattler-build" %}
-    {{ BUILD_CMD }} ./{{ recipe_dir }} -m ./.ci_support/${CONFIG}.yaml \
+    CONDA_SUBDIR="${BUILD_PLATFORM}" {{ BUILD_CMD }} ./{{ recipe_dir }} -m ./.ci_support/${CONFIG}.yaml \
         --suppress-variables ${EXTRA_CB_OPTIONS:-} \
         --clobber-file ./.ci_support/clobber_${CONFIG}.yaml \
         --extra-meta flow_run_id="$flow_run_id" remote_url="$remote_url" sha="$sha"
@@ -198,6 +199,7 @@ else
     {{ BUILD_CMD }} --recipe ./{{ recipe_dir }} \
         -m ./.ci_support/${CONFIG}.yaml \
         ${EXTRA_CB_OPTIONS:-} \
+        --build-platform "${BUILD_PLATFORM}" \
         --target-platform "${HOST_PLATFORM}" \
         --extra-meta flow_run_id="$flow_run_id" \
         --extra-meta remote_url="$remote_url" \
diff --git a/conda_smithy/templates/run_win_build.bat.tmpl b/conda_smithy/templates/run_win_build.bat.tmpl
index 51048ec1d..4ca19f4a1 100644
--- a/conda_smithy/templates/run_win_build.bat.tmpl
+++ b/conda_smithy/templates/run_win_build.bat.tmpl
@@ -68,7 +68,8 @@ if "%PIXI_CACHE_DIR%"=="%MINIFORGE_HOME%" (
 )
 move /y pixi.toml pixi.toml.bak
 set "arch=64"
-if "%PROCESSOR_ARCHITECTURE%"=="ARM64" set "arch=arm64"
+{#- TODO: Enable this line again once we have bootstrapped all the dependencies for a full base environment on win-arm64; emulate win-64 for now  #}
+{#- if "%PROCESSOR_ARCHITECTURE%"=="ARM64" set "arch=arm64" #}
 powershell -NoProfile -ExecutionPolicy unrestricted -Command "(Get-Content pixi.toml.bak -Encoding UTF8) -replace 'platforms = .*', 'platforms = [''win-%arch%'']' | Out-File pixi.toml -Encoding UTF8"
 :: Git on Windows needs to run post link scripts to properly set up SSL certificates
 pixi config set --global run-post-link-scripts insecure
@@ -182,6 +183,10 @@ call :end_group
 
 :: Build the recipe
 echo Building recipe
+{%- if conda_build_tool.startswith(("conda-build", "mambabuild")) %}
+set "_OLD_CONDA_SUBDIR=%CONDA_SUBDIR%"
+set "CONDA_SUBDIR=%BUILD_PLATFORM%"
+{%- endif %}
 {%- if conda_build_tool == "mambabuild" %}
 conda-mambabuild.exe "{{ recipe_dir }}" -m .ci_support\%CONFIG%.yaml --suppress-variables %EXTRA_CB_OPTIONS%
 {%- elif conda_build_tool == "conda-build+conda-libmamba-solver" %}
@@ -193,9 +198,13 @@ conda-build.exe "{{ recipe_dir }}" -m .ci_support\%CONFIG%.yaml --suppress-varia
 {%- elif conda_build_tool == "conda-build" %}
 conda-build.exe "{{ recipe_dir }}" -m .ci_support\%CONFIG%.yaml --suppress-variables %EXTRA_CB_OPTIONS%
 {%- elif conda_build_tool == "rattler-build" %}
-rattler-build.exe build --recipe "{{ recipe_dir }}" -m .ci_support\%CONFIG%.yaml %EXTRA_CB_OPTIONS% --target-platform %HOST_PLATFORM%
+rattler-build.exe build --recipe "{{ recipe_dir }}" -m .ci_support\%CONFIG%.yaml %EXTRA_CB_OPTIONS% --build-platform %BUILD_PLATFORM% --target-platform %HOST_PLATFORM%
 {%- endif %}
 if !errorlevel! neq 0 exit /b !errorlevel!
+{%- if conda_build_tool.startswith(("conda-build", "mambabuild")) %}
+set "_OLD_CONDA_SUBDIR="
+set "CONDA_SUBDIR=%_OLD_CONDA_SUBDIR%"
+{%- endif %}
 
 call :start_group "Inspecting artifacts"
 :: inspect_artifacts was only added in conda-forge-ci-setup 4.9.4
diff --git a/news/2622-build-platform.rst b/news/2622-build-platform.rst
new file mode 100644
index 000000000..ddb252281
--- /dev/null
+++ b/news/2622-build-platform.rst
@@ -0,0 +1,24 @@
+**Added:**
+
+* <news item>
+
+**Changed:**
+
+* ``rattler-build`` and ``conda-build`` are now called explicit build platforms (via ``--build-platform`` and ``CONDA_SUBDIR``, respectively). (#2622)
+* On Windows ARM machines, ``pixi`` will always provision ``win-64`` tooling while the ``win-arm64`` platform is being bootstrapped. (#2622)
+
+**Deprecated:**
+
+* <news item>
+
+**Removed:**
+
+* <news item>
+
+**Fixed:**
+
+* <news item>
+
+**Security:**
+
+* <news item>