diff --git a/.github/actions/install-build-tools/action.yml b/.github/actions/install-build-tools/action.yml
index 4b9ae7d820..0c1afbf0b9 100644
--- a/.github/actions/install-build-tools/action.yml
+++ b/.github/actions/install-build-tools/action.yml
@@ -15,7 +15,7 @@ runs:
         git config --global core.preloadindex true
         git config --global core.longpaths true
       fi
-      export BUILD_TOOLS_SHA=4430e4a505e0f4fa2a41b707a10a36f780bbdd26
+      export BUILD_TOOLS_SHA=a0cc95a1884a631559bcca0c948465b725d9295a
       npm i -g @electron/build-tools
       # Update depot_tools to ensure python
       e d update_depot_tools
diff --git a/build/siso/backend.star b/build/siso/backend.star
deleted file mode 100644
index b729ccb689..0000000000
--- a/build/siso/backend.star
+++ /dev/null
@@ -1,21 +0,0 @@
-# -*- bazel-starlark -*-
-
-load("@builtin//struct.star", "module")
-
-def __platform_properties(ctx):
-    container_image = "docker://gcr.io/chops-public-images-prod/rbe/siso-chromium/linux@sha256:d7cb1ab14a0f20aa669c23f22c15a9dead761dcac19f43985bf9dd5f41fbef3a"
-    return {
-        "default": {
-            "OSFamily": "Linux",
-            "container-image": container_image,
-        },
-        "large": {
-            "OSFamily": "Linux",
-            "container-image": container_image,
-        },
-    }
-
-backend = module(
-    "backend",
-    platform_properties = __platform_properties,
-)
diff --git a/build/siso/main.star b/build/siso/main.star
deleted file mode 100644
index dab7e118a1..0000000000
--- a/build/siso/main.star
+++ /dev/null
@@ -1,66 +0,0 @@
-load("@builtin//encoding.star", "json")
-load("@builtin//path.star", "path")
-load("@builtin//runtime.star", "runtime")
-load("@builtin//struct.star", "module")
-load("@config//main.star", upstream_init = "init")
-load("@config//win_sdk.star", "win_sdk")
-load("@config//gn_logs.star", "gn_logs")
-
-def init(ctx):
-    mod = upstream_init(ctx)
-    step_config = json.decode(mod.step_config)
-
-    # Buildbarn doesn't support input_root_absolute_path so disable that
-    for rule in step_config["rules"]:    
-      input_root_absolute_path = rule.get("input_root_absolute_path", False)
-      if input_root_absolute_path:
-        rule.pop("input_root_absolute_path", None)
-
-    # Only wrap clang rules with a remote wrapper if not on Linux. These are currently only
-    # needed for X-Compile builds, which run on Windows and Mac.
-    if runtime.os != "linux":
-      for rule in step_config["rules"]:
-        if rule["name"].startswith("clang/") or rule["name"].startswith("clang-cl/"):
-          rule["remote_wrapper"] = "../../buildtools/reclient_cfgs/chromium-browser-clang/clang_remote_wrapper"
-          if "inputs" not in rule:
-            rule["inputs"] = []
-          rule["inputs"].append("buildtools/reclient_cfgs/chromium-browser-clang/clang_remote_wrapper")
-          rule["inputs"].append("third_party/llvm-build/Release+Asserts_linux/bin/clang")
-
-      if "executables" not in step_config:
-        step_config["executables"] = []
-      step_config["executables"].append("buildtools/reclient_cfgs/chromium-browser-clang/clang_remote_wrapper")
-      step_config["executables"].append("third_party/llvm-build/Release+Asserts_linux/bin/clang")
-
-    if runtime.os == "darwin":
-      # Update platforms to match our default siso config instead of reclient configs.
-      step_config["platforms"].update({
-          "clang": step_config["platforms"]["default"],
-          "clang_large": step_config["platforms"]["default"],          
-      })      
-
-    if runtime.os == "windows":
-      # Add additional Windows SDK headers needed by Electron      
-      win_toolchain_dir = win_sdk.toolchain_dir(ctx)
-      if win_toolchain_dir:
-        sdk_version = gn_logs.read(ctx).get("windows_sdk_version")
-        step_config["input_deps"][win_toolchain_dir + ":headers"].extend([
-          # third_party/electron_node/deps/uv/include/uv/win.h includes mswsock.h
-          path.join(win_toolchain_dir, "Windows Kits/10/Include", sdk_version, "um/mswsock.h"),
-          # third_party/electron_node/src/debug_utils.cc includes lm.h
-          path.join(win_toolchain_dir, "Windows Kits/10/Include", sdk_version, "um/Lm.h"),          
-        ])
-      
-      # Update platforms to match our default siso config instead of reclient configs.
-      step_config["platforms"].update({
-          "clang-cl": step_config["platforms"]["default"],
-          "clang-cl_large": step_config["platforms"]["default"],
-          "lld-link": step_config["platforms"]["default"],
-      })
-
-    return module(
-      "config",
-      step_config = json.encode(step_config),
-      filegroups = mod.filegroups,
-      handlers = mod.handlers,
-    )