diff --git a/tools/bots/test_matrix.json b/tools/bots/test_matrix.json
index e01a35f366b..d795d61dfd7 100644
--- a/tools/bots/test_matrix.json
+++ b/tools/bots/test_matrix.json
@@ -1119,19 +1119,11 @@
         "description": "This configuration is used by the vm kbc builders."
       },
       "steps": [
-        {
-          "name": "configure dart",
-          "script": "tools/gn.py",
-          "arguments": [
-            "--mode=${mode}",
-            "--arch=${arch}",
-            "--bytecode"
-          ]
-        },
         {
           "name": "build dart",
           "script": "tools/build.py",
           "arguments": [
+            "--bytecode",
             "runtime"
           ]
         },
@@ -1273,17 +1265,11 @@
         "description": "This configuration is used for running FFI tests on qemu."
       },
       "steps": [
-        {
-          "name": "configure dart",
-          "script": "tools/gn.py",
-          "arguments": [
-            "--use-qemu"
-          ]
-        },
         {
           "name": "build dart",
           "script": "tools/build.py",
           "arguments": [
+            "--use-qemu",
             "dart_precompiled_runtime",
             "runtime_kernel"
           ]
@@ -1526,11 +1512,6 @@
         "description": "This configuration is used by the VM/JIT builders with sanitizers."
       },
       "steps": [
-        {
-          "name": "configure dart",
-          "script": "tools/gn.py",
-          "arguments": []
-        },
         {
           "name": "build dart",
           "script": "tools/build.py",
@@ -1554,11 +1535,6 @@
         "description": "This configuration is used by the VM/JIT builders with sanitizers."
       },
       "steps": [
-        {
-          "name": "configure dart",
-          "script": "tools/gn.py",
-          "arguments": []
-        },
         {
           "name": "build dart",
           "script": "tools/build.py",
@@ -1586,11 +1562,6 @@
         "description": "This configuration is used by the VM/AOT builders with sanitizers."
       },
       "steps": [
-        {
-          "name": "configure dart",
-          "script": "tools/gn.py",
-          "arguments": []
-        },
         {
           "name": "build dart",
           "script": "tools/build.py",
@@ -1617,11 +1588,6 @@
         "description": "This configuration is used by the VM/AOT builders with sanitizers."
       },
       "steps": [
-        {
-          "name": "configure dart",
-          "script": "tools/gn.py",
-          "arguments": []
-        },
         {
           "name": "build dart",
           "script": "tools/build.py",
@@ -1647,22 +1613,14 @@
         "description": "This configuration builds the VM with GCC."
       },
       "steps": [
-        {
-          "name": "configure dart",
-          "script": "tools/gn.py",
-          "arguments": [
-            "--mode=all",
-            "--arch=all",
-            "--no-clang",
-            "--no-goma"
-          ]
-        },
         {
           "name": "build dart",
           "script": "tools/build.py",
           "arguments": [
             "--mode=all",
             "--arch=all",
+            "--no-clang",
+            "--no-goma",
             "runtime"
           ]
         }
@@ -3488,21 +3446,11 @@
         "description": "This configuration runs tests for each supported ABI version."
       },
       "steps": [
-        {
-          "name": "configure dart",
-          "script": "tools/gn.py",
-          "arguments": [
-            "--mode=release",
-            "--arch=x64",
-            "--bytecode"
-          ]
-        },
         {
           "name": "build dart",
           "script": "tools/build.py",
           "arguments": [
-            "--mode=release",
-            "--arch=x64",
+            "--bytecode",
             "create_sdk_with_abi_versions"
           ]
         },
@@ -3523,30 +3471,11 @@
         "description": "This configuration runs tests for the simarm_x64 architecture."
       },
       "steps": [
-        {
-          "name": "configure dart for simarm_x64",
-          "script": "tools/gn.py",
-          "arguments": [
-            "--mode=${mode}",
-            "--arch=simarm_x64",
-            "--bytecode"
-          ]
-        },
-        {
-          "name": "configure dart for simarm",
-          "script": "tools/gn.py",
-          "arguments": [
-            "--mode=${mode}",
-            "--arch=simarm",
-            "--bytecode"
-          ]
-        },
         {
           "name": "build dart for simarm_x64",
           "script": "tools/build.py",
           "arguments": [
-            "--mode=${mode}",
-            "--arch=simarm_x64",
+            "--bytecode",
             "gen_snapshot"
           ]
         },
@@ -3554,8 +3483,8 @@
           "name": "build dart for simarm",
           "script": "tools/build.py",
           "arguments": [
-            "--mode=${mode}",
             "--arch=simarm",
+            "--bytecode",
             "dart_precompiled_runtime",
             "vm_platform"
           ]
diff --git a/tools/build.py b/tools/build.py
index e9cb287623b..6b78ddc4f5b 100755
--- a/tools/build.py
+++ b/tools/build.py
@@ -115,48 +115,6 @@ def NotifyBuildDone(build_config, success, start):
         # Ignore return code, if this command fails, it doesn't matter.
         os.system(command)
 
-
-def GenerateBuildfilesIfNeeded():
-    if os.path.exists(utils.GetBuildDir(HOST_OS)):
-        return True
-    command = [
-        'python',
-        os.path.join(DART_ROOT, 'tools', 'generate_buildfiles.py')
-    ]
-    print("Running " + ' '.join(command))
-    process = subprocess.Popen(command)
-    process.wait()
-    if process.returncode != 0:
-        print("Tried to generate missing buildfiles, but failed. "
-              "Try running manually:\n\t$ " + ' '.join(command))
-        return False
-    return True
-
-
-def RunGNIfNeeded(out_dir, target_os, mode, arch, sanitizer):
-    if os.path.isfile(os.path.join(out_dir, 'args.gn')):
-        return
-    gn_os = 'host' if target_os == HOST_OS else target_os
-    gn_command = [
-        'python',
-        os.path.join(DART_ROOT, 'tools', 'gn.py'),
-        '--sanitizer',
-        sanitizer,
-        '-m',
-        mode,
-        '-a',
-        arch,
-        '--os',
-        gn_os,
-        '-v',
-    ]
-
-    process = subprocess.Popen(gn_command)
-    process.wait()
-    if process.returncode != 0:
-        print("Tried to run GN, but it failed. Try running it manually: \n\t$ "
-              + ' '.join(gn_command))
-
 def UseGoma(out_dir):
     args_gn = os.path.join(out_dir, 'args.gn')
     return 'use_goma = true' in open(args_gn, 'r').read()
@@ -205,8 +163,6 @@ def BuildOneConfig(options, targets, target_os, mode, arch, sanitizer):
     build_config = utils.GetBuildConf(mode, arch, target_os, sanitizer)
     out_dir = utils.GetBuildRoot(HOST_OS, mode, arch, target_os, sanitizer)
     using_goma = False
-    # TODO(kustermann): Remove this once we always run GN.
-    RunGNIfNeeded(out_dir, target_os, mode, arch, sanitizer)
     command = ['ninja', '-C', out_dir]
     if options.verbose:
         command += ['-v']
@@ -280,9 +236,6 @@ def Main():
         parser.print_help()
         return 1
 
-    if not GenerateBuildfilesIfNeeded():
-        return 1
-
     # If binaries are built with sanitizers we should use those flags.
     # If the binaries are not built with sanitizers the flag should have no
     # effect.
@@ -290,8 +243,7 @@ def Main():
     env.update(SanitizerEnvironmentVariables())
 
     # Always run GN before building.
-    # TODO(kustermann): Once recipe change landed we should enable this again.
-    # gn_py.RunGnOnConfiguredConfigurations(options)
+    gn_py.RunGnOnConfiguredConfigurations(options)
 
     # Build all targets for each requested configuration.
     configs = []
diff --git a/tools/run_offsets_extractor.sh b/tools/run_offsets_extractor.sh
index c55cc2454e3..8675fea7989 100755
--- a/tools/run_offsets_extractor.sh
+++ b/tools/run_offsets_extractor.sh
@@ -25,7 +25,6 @@ head -n $(expr $LINE - 1) "$FILE" >"$TEMP_HEADER"
 
 # Run offsets_extractor for every architecture and append the results.
 run() {
-  tools/gn.py --mode=$1 --arch=$2
   tools/build.py --mode=$1 --arch=$2 offsets_extractor offsets_extractor_precompiled_runtime
   echo "" >>"$TEMP_JIT"
   out/$3/offsets_extractor >>"$TEMP_JIT"