diff --git a/packages/bazel/src/ng_module/ng_module.bzl b/packages/bazel/src/ng_module/ng_module.bzl
index 66543c65832..fd55368d34e 100644
--- a/packages/bazel/src/ng_module/ng_module.bzl
+++ b/packages/bazel/src/ng_module/ng_module.bzl
@@ -60,7 +60,7 @@ def _flat_module_out_file(ctx):
     from other attributes (name)
 
     Args:
-      ctx: skylark rule execution context
+      ctx: starlark rule execution context
 
     Returns:
       a basename used for the flat module out (no extension)
@@ -76,7 +76,7 @@ def _should_produce_flat_module_outs(ctx):
     based on the presence of the module_name attribute.
 
     Args:
-      ctx: skylark rule execution context
+      ctx: starlark rule execution context
 
     Returns:
       true iff we should run the bundle_index_host to produce flat module metadata and bundle index
@@ -118,7 +118,7 @@ def _expected_outs(ctx):
             else:
                 devmode_js = [".js"]
                 if not _is_bazel():
-                    devmode_js += [".ngfactory.js"]
+                    devmode_js.append(".ngfactory.js")
         else:
             continue
 
@@ -238,17 +238,13 @@ def _ngc_tsconfig(ctx, files, srcs, **kwargs):
     })
 
     # For prodmode, the compilation target is set to `ES2020`. `@bazel/typecript`
-    # using the `create_tsconfig` function sets `ES2015` by default.
+    # using the `create_tsconfig` function sets `ES2015` by default for prodmode
+    # and uses ES5 with UMD for devmode. We want to consistenly use ES2020 ESM.
     # https://github.com/bazelbuild/rules_nodejs/blob/901df3868e3ceda177d3ed181205e8456a5592ea/third_party/github.com/bazelbuild/rules_typescript/internal/common/tsconfig.bzl#L195
     # TODO(devversion): In the future, combine prodmode and devmode so we can get rid of the
     # ambiguous terminology and concept that can result in slow-down for development workflows.
-    if not is_devmode:
-        # Note: Keep in sync with the `prodmode_target` for `ts_library` in `tools/defaults.bzl`
-        tsconfig["compilerOptions"]["target"] = "es2020"
-    else:
-        # For devmode output, we use ES2015 to match with what `ts_library` produces by default.
-        # https://github.com/bazelbuild/rules_nodejs/blob/9b36274dba34204625579463e3da054a9f42cb47/packages/typescript/internal/build_defs.bzl#L83.
-        tsconfig["compilerOptions"]["target"] = "es2015"
+    tsconfig["compilerOptions"]["target"] = "es2020"
+    tsconfig["compilerOptions"]["module"] = "esnext"
 
     return tsconfig
 
@@ -278,7 +274,7 @@ def ngc_compile_action(
     as part of the public API.
 
     Args:
-      ctx: skylark context
+      ctx: starlark context
       label: the label of the ng_module being compiled
       inputs: passed to the ngc action's inputs
       outputs: passed to the ngc action's outputs
@@ -315,7 +311,7 @@ def ngc_compile_action(
     # Two at-signs escapes the argument so it's passed through to ngc
     # rather than the contents getting expanded.
     if supports_workers == "1":
-        arguments += ["@@" + tsconfig_file.path]
+        arguments.append("@@" + tsconfig_file.path)
     else:
         arguments += ["-p", tsconfig_file.path]
 
@@ -414,7 +410,7 @@ def ng_module_impl(ctx, ts_compile_actions):
     and is not meant as a public API.
 
     Args:
-      ctx: the skylark rule context
+      ctx: the starlark rule context
       ts_compile_actions: generates all the actions to run an ngc compilation
 
     Returns:
diff --git a/tools/defaults.bzl b/tools/defaults.bzl
index 6775e610219..e7de068ed44 100644
--- a/tools/defaults.bzl
+++ b/tools/defaults.bzl
@@ -102,7 +102,17 @@ def ts_devserver(**kwargs):
 
 ts_config = _ts_config
 
-def ts_library(name, tsconfig = None, testonly = False, deps = [], module_name = None, package_name = None, **kwargs):
+def ts_library(
+        name,
+        tsconfig = None,
+        testonly = False,
+        deps = [],
+        module_name = None,
+        package_name = None,
+        # TODO(devversion): disallow configuration of the target when binaries/schematics can be ESM.
+        devmode_target = None,
+        devmode_module = None,
+        **kwargs):
     """Default values for ts_library"""
     deps = deps + ["@npm//tslib"]
     if testonly:
@@ -122,16 +132,24 @@ def ts_library(name, tsconfig = None, testonly = False, deps = [], module_name =
     if not package_name:
         package_name = _default_module_name(testonly)
 
+    default_target = "es2020"
+    default_module = "esnext"
+
     _ts_library(
         name = name,
         tsconfig = tsconfig,
         testonly = testonly,
         deps = deps,
+        # We also set devmode output to the same settings as prodmode as a first step in
+        # combining devmode and prodmode output.
+        devmode_target = devmode_target if devmode_target != None else default_target,
+        devmode_module = devmode_module if devmode_module != None else default_module,
         # For prodmode, the target is set to `ES2020`. `@bazel/typecript` sets `ES2015` by
         # default. Note that this should be in sync with the `ng_module` tsconfig generation.
         # https://github.com/bazelbuild/rules_nodejs/blob/901df3868e3ceda177d3ed181205e8456a5592ea/third_party/github.com/bazelbuild/rules_typescript/internal/common/tsconfig.bzl#L195
         # https://github.com/bazelbuild/rules_nodejs/blob/9b36274dba34204625579463e3da054a9f42cb47/packages/typescript/internal/build_defs.bzl#L85.
-        prodmode_target = "es2020",
+        prodmode_target = default_target,
+        prodmode_module = default_module,
         # `module_name` is used for AMD module names within emitted JavaScript files.
         module_name = module_name,
         # `package_name` can be set to allow for the Bazel NodeJS linker to run. This